Commit f81ce56b authored by chenzk's avatar chenzk
Browse files

vllm kvprune:v1.0.1

parent 2b7160c6
import os
from dataclasses import dataclass
from enum import Enum, auto
from typing import List, Optional
from transformers import AutoConfig
class AttentionBackend(Enum):
"""Legacy coarse backend toggle (prefer :class:`KvpruneAttentionSchedule`)."""
FLASH_ATTENTION = auto()
COMPACTOR_TRITON = auto()
class KvpruneAttentionSchedule(Enum):
"""FlashAttention vs Triton split for prefill / decode (KV **writes** stay Triton)."""
# Default: FA varlen prefill; decode uses ``head_sparse_decode_attention`` (Triton).
FA_PREFILL_TRITON_DECODE = auto()
# Prefill attention uses ``causal_sparse_varlen_with_cache`` (Triton); decode Triton.
TRITON_PREFILL_TRITON_DECODE = auto()
# "PDFA": FA prefill + FA decode; paged KV **storage** (incl. pruned top-k) unchanged.
PDFA = auto()
@dataclass
class LLMConfig:
"""Configuration for the :class:`LLM` engine.
Parameters
----------
model : str
Hugging Face model identifier (e.g. ``"meta-llama/Meta-Llama-3-8B"``) or
a local model name that can be resolved by
:func:`transformers.AutoConfig.from_pretrained`.
path : str, optional
Local directory containing the model weights. If ``None``, the engine
will attempt to resolve a local snapshot for ``model`` using
:func:`huggingface_hub.snapshot_download`.
max_num_seqs : int, default 256
Upper bound on the number of concurrent batches that the scheduler and
KV-cache manager are allowed to handle. This affects the size of the
page table and some internal buffers.
max_model_len : int, default 40960
Maximum context length (in tokens) that the engine will allocate KV cache
and CUDA graphs for. During initialization this value is clamped to
``hf_config.max_position_embeddings`` for the chosen model.
gpu_memory_utilization : float, default 0.9
Fraction of the total GPU memory that may be used for KV cache and model
activations. Values should be in ``(0, 1]``. If this budget is too small,
the KV-cache manager may raise an error at warmup time due
to insufficient memory.
tensor_parallel_size : int, default 1
Number of tensor-parallel workers to shard the model
across. Must be between 1 and 8, and must evenly divide the model's
number of key/value heads.
enforce_eager : bool, default False
If ``True``, disable CUDA graph capture and always run the model in
eager mode during decoding. This reduces throughput. When ``False``,
the engine will capture and reuse CUDA graphs for supported
batch sizes and sequence lengths.
hf_config : transformers.AutoConfig, optional
Pre-loaded Hugging Face configuration for the model. If ``None``,
it will then be populated automatically based on ``model``.
eos : int, default -1
Primary stop token id (warmup / single-id paths). If ``-1``, the
:class:`LLM` constructor fills this and :attr:`eos_token_ids` from the
tokenizer.
eos_token_ids : list of int, optional
All token ids that terminate generation (e.g. HF tokenizers may expose
``eos_token_id`` as a list for chat models). If ``None``, inferred in
:class:`LLM` from the tokenizer and model type.
kvcache_page_size : int, default 128
Number of tokens stored in a single KV-cache page. Smaller pages improve
allocation flexibility but increase page-table overhead; larger pages
reduce overhead but have coarser granularity.
leverage_sketch_size : int, default 48
Sketch dimension used by the Compactor leverage-score estimator.
attention_schedule : KvpruneAttentionSchedule, default FA_PREFILL_TRITON_DECODE
Which **attention** implementation runs on prefill vs decode. KV **writes**
(``prefill_store_*``, ``decode_store_kv``, pruned top-k) always use the
existing Triton store kernels. Env ``VLLM_KVPRUNE_ATTENTION_SCHEDULE`` uses
short names: ``fa_triton`` (default), ``pdtriton``, ``pdfa``. Enum values:
``FA_PREFILL_TRITON_DECODE`` — FA prefill, Triton decode;
``TRITON_PREFILL_TRITON_DECODE`` — Triton prefill + decode;
``PDFA`` — FA prefill + FA decode (still Triton KV I/O).
attention_backend : AttentionBackend, optional
Deprecated. Ignored if ``attention_schedule`` is set; otherwise mapped
for backward compatibility.
"""
model: str
path: Optional[str] = None
nccl_port: Optional[int] = 1218
max_num_seqs: int = 256
max_model_len: int = 40960
gpu_memory_utilization: float = 0.9
tensor_parallel_size: int = 1
enforce_eager: bool = False
hf_config: AutoConfig | None = None
eos: int = -1
eos_token_ids: Optional[List[int]] = None
kvcache_page_size: int = 128
leverage_sketch_size: int = 48
attention_schedule: KvpruneAttentionSchedule = (
KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
)
attention_backend: AttentionBackend | None = None
show_progress_bar: bool = True
def __post_init__(self):
if self.attention_backend is not None:
if self.attention_backend == AttentionBackend.FLASH_ATTENTION:
self.attention_schedule = KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
else:
self.attention_schedule = (
KvpruneAttentionSchedule.TRITON_PREFILL_TRITON_DECODE
)
if self.path is not None and not os.path.isdir(self.path):
raise NotADirectoryError(f"Engine config dir {self.path} does not exist")
if self.tensor_parallel_size <= 0 or self.tensor_parallel_size > 8:
assert 1 <= self.tensor_parallel_size <= 8
raise ValueError("tensor_parallel_size must be >= 1 and <= 8")
if self.hf_config is None:
self.hf_config = AutoConfig.from_pretrained(self.model)
self.max_model_len = min(
self.max_model_len, self.hf_config.max_position_embeddings
)
from dataclasses import dataclass
@dataclass
class SamplingParams:
temperature: float = 1.0
max_new_tokens: int = 256
def __post_init__(self):
if self.temperature < 0:
raise ValueError("Temperature cannot be negative")
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Core: compactor ``LLMEngine`` stack (``llm_engine``, ``scheduler``, …) plus helpers
(``runtime``, ``flash_integration``, ``block_budget``) used **inside** the compactor path.
v1 does not import these; use :meth:`vllm.LLM.generate` with ``compression=`` for the
``LLM`` + compactor integration.
"""
from vllm.kvprune.core.block_budget import (
TailReclaimHint,
build_tail_reclaim_hint,
tail_blocks_if_logical_shorter,
)
from vllm.kvprune.core.compression_bridge import (
VALID_ALIASES_FOR_SAMPLING,
compression_method_id_to_enum,
compression_method_str_to_id,
)
from vllm.kvprune.core.flash_integration import (
do_kv_cache_update_kv_prune,
merge_seq_lens_with_kv_prune,
)
from vllm.kvprune.core.runtime import (
KVPruneForwardState,
build_kv_prune_forward_state,
get_kv_prune_state,
layer_index_from_layer_name,
)
__all__ = [
"KVPruneForwardState",
"TailReclaimHint",
"VALID_ALIASES_FOR_SAMPLING",
"build_kv_prune_forward_state",
"build_tail_reclaim_hint",
"compression_method_id_to_enum",
"compression_method_str_to_id",
"do_kv_cache_update_kv_prune",
"get_kv_prune_state",
"layer_index_from_layer_name",
"merge_seq_lens_with_kv_prune",
"tail_blocks_if_logical_shorter",
]
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Block budget helpers for compactor KV pruning (logical vs physical length).
Used by the **compactor** ``LLMEngine`` path (``PagedKVCache`` / logical lengths),
not by v1's scheduler. The helpers compare logical KV length to a physical token
count and return how many full tail blocks can be reclaimed when logical shrinks.
"""
from __future__ import annotations
from dataclasses import dataclass
@dataclass(frozen=True)
class TailReclaimHint:
"""How many tail blocks could be freed if logical KV shrinks below allocation."""
request_id: str
allocated_tokens: int
logical_tokens: int
block_size: int
reclaimable_tail_blocks: int
def tail_blocks_if_logical_shorter(
allocated_tokens: int,
logical_tokens: int,
block_size: int,
) -> int:
"""Return count of fully-unused tail blocks when ``logical < allocated``.
Block-granular: only counts whole blocks past the last block that still
contains a retained logical token index.
"""
if block_size <= 0:
return 0
if logical_tokens >= allocated_tokens:
return 0
# Last logical token occupies block index floor((logical-1)/bs) if logical>0
if logical_tokens <= 0:
return (allocated_tokens + block_size - 1) // block_size
last_logical_block = (logical_tokens - 1) // block_size
last_alloc_block = (allocated_tokens - 1) // block_size
return max(0, last_alloc_block - last_logical_block)
def build_tail_reclaim_hint(
request_id: str,
allocated_tokens: int,
logical_tokens: int,
block_size: int,
) -> TailReclaimHint:
n = tail_blocks_if_logical_shorter(allocated_tokens, logical_tokens, block_size)
return TailReclaimHint(
request_id=request_id,
allocated_tokens=allocated_tokens,
logical_tokens=logical_tokens,
block_size=block_size,
reclaimable_tail_blocks=n,
)
__all__ = [
"TailReclaimHint",
"build_tail_reclaim_hint",
"tail_blocks_if_logical_shorter",
]
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Map compression method strings (e.g. from :class:`~vllm.kvprune.integration.CompressionParams`) to kvprune GPU / enum IDs."""
from __future__ import annotations
from vllm.kvprune.compression.compression_config import CompressionMethod
# IDs stored on device [num_reqs_padded] (int32). Order is stable for kernels.
COMPRESSION_METHOD_ID_NONE = 0
COMPRESSION_METHOD_ID_CRITICALADAKV = 1
COMPRESSION_METHOD_ID_COMPACTOR = 2
COMPRESSION_METHOD_ID_SNAPKV = 3
# Aliases accepted for method strings (case-insensitive after strip).
VALID_ALIASES_FOR_SAMPLING: frozenset[str] = frozenset(
{"none", "criticaladakv", "compactor", "snapkv"}
)
_STR_TO_ID: dict[str, int] = {
"none": COMPRESSION_METHOD_ID_NONE,
"criticaladakv": COMPRESSION_METHOD_ID_CRITICALADAKV,
"compactor": COMPRESSION_METHOD_ID_COMPACTOR,
"snapkv": COMPRESSION_METHOD_ID_SNAPKV,
}
_ID_TO_COMPRESSION_METHOD: dict[int, CompressionMethod] = {
COMPRESSION_METHOD_ID_NONE: CompressionMethod.NONE,
COMPRESSION_METHOD_ID_CRITICALADAKV: CompressionMethod.CRITICALADAKV,
COMPRESSION_METHOD_ID_COMPACTOR: CompressionMethod.COMPACTOR,
COMPRESSION_METHOD_ID_SNAPKV: CompressionMethod.SNAPKV,
}
def compression_method_str_to_id(s: str) -> int:
"""Normalize and map user string to a stable int id (0..3)."""
key = (s or "none").strip().lower()
if key not in _STR_TO_ID:
raise ValueError(
f"Unknown compression_method {s!r}; expected one of "
f"{sorted(VALID_ALIASES_FOR_SAMPLING)}"
)
return _STR_TO_ID[key]
def compression_method_id_to_enum(method_id: int) -> CompressionMethod:
if method_id not in _ID_TO_COMPRESSION_METHOD:
return CompressionMethod.NONE
return _ID_TO_COMPRESSION_METHOD[method_id]
__all__ = [
"COMPRESSION_METHOD_ID_NONE",
"COMPRESSION_METHOD_ID_CRITICALADAKV",
"COMPRESSION_METHOD_ID_COMPACTOR",
"COMPRESSION_METHOD_ID_SNAPKV",
"VALID_ALIASES_FOR_SAMPLING",
"compression_method_id_to_enum",
"compression_method_str_to_id",
]
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""FlashAttention + KV cache hooks for kvprune."""
from __future__ import annotations
import torch
from vllm.kvprune.core.runtime import KVPruneForwardState, get_kv_prune_state
_RATIO_ONE = 1.0 - 1e-6
def merge_seq_lens_with_kv_prune(
base_seq_lens: torch.Tensor,
layer_name: str,
max_query_len: int,
) -> torch.Tensor:
"""Blend scheduler seq_lens with per-layer logical lengths when pruning."""
state = get_kv_prune_state()
if state is None:
return base_seq_lens
# Prefill: only scheduler lengths are reliable unless compactor store ran for
# every layer (try_prefill_kv_store); when pruning is requested but ineligible
# (e.g. unsupported dtype), logical buffers may still be zero — do not override.
if max_query_len > 1:
return base_seq_lens
layer_idx = _layer_idx(layer_name)
num_reqs = state.num_reqs
comp = state.compression_ratio_gpu[:num_reqs]
logical = state.logical_seq_lens_gpu[layer_idx, :num_reqs]
if logical.dim() == 2:
logical = logical.max(dim=-1).values
out = base_seq_lens.clone()
use_logical = comp < _RATIO_ONE
out[:num_reqs] = torch.where(
use_logical,
logical.to(out.dtype),
base_seq_lens[:num_reqs],
)
return out
def _layer_idx(layer_name: str) -> int:
from vllm.kvprune.core.runtime import layer_index_from_layer_name
return layer_index_from_layer_name(layer_name)
def do_kv_cache_update_kv_prune(
layer: torch.nn.Module,
key: torch.Tensor,
value: torch.Tensor,
kv_cache: torch.Tensor,
slot_mapping: torch.Tensor,
reshape_and_cache_flash,
kv_cache_dtype: str,
) -> bool:
"""If kvprune handles this step, return True (caller skips default path)."""
state = get_kv_prune_state()
if state is None:
return False
layer_idx = _layer_idx(layer.layer_name)
num_reqs = state.num_reqs
if state.is_prefill:
from vllm.kvprune.compression.prefill import try_prefill_kv_store
if try_prefill_kv_store(layer, key, value, kv_cache):
return True
return False
key_cache, value_cache = kv_cache.unbind(0)
reshape_and_cache_flash(
key,
value,
key_cache,
value_cache,
slot_mapping,
kv_cache_dtype,
layer._k_scale,
layer._v_scale,
)
comp = state.compression_ratio_gpu[:num_reqs]
mask = (comp < _RATIO_ONE).to(torch.int32)
layer_buf = state.logical_seq_lens_gpu[layer_idx, :num_reqs]
if layer_buf.dim() == 2:
layer_buf += mask.unsqueeze(-1)
else:
layer_buf += mask
return True
from __future__ import annotations
import atexit
import inspect
import logging
from pathlib import Path
from typing import Any, List, Optional, Union
import torch.nn as nn
import torch.multiprocessing as mp
from vllm.kvprune.compression.compression_config import (
BatchCompressionParams,
SequenceCompressionParams,
)
from vllm.kvprune.config.engine_config import LLMConfig
from vllm.kvprune.config.sampling_params import SamplingParams
from vllm.kvprune.core.model_runner import ModelRunner
from vllm.kvprune.models import MODEL_REGISTRY
from vllm.kvprune.utils.sequence import Sequence
from transformers import AutoTokenizer
logger = logging.getLogger(__name__)
PromptLike = Union[str, List[int]]
def _infer_stop_token_ids(tokenizer, hf_config) -> list[int]:
"""
Build the set of token ids that should end generation.
Newer HF chat tokenizers often expose ``eos_token_id`` as a *list* of ids.
The engine must not compare generated ids to that list as a single ``int``;
see :attr:`LLMConfig.eos_token_ids` and decode-time ``torch.isin``.
Qwen chat uses ``</think>`` (im_end) as the assistant turn boundary; include it
when present in ``additional_special_tokens`` / ``added_tokens_encoder``. We
avoid loose substring matches like ``\"end\"`` that can tag unrelated tokens.
"""
raw = tokenizer.eos_token_id
ids: list[int] = []
if isinstance(raw, (list, tuple)):
ids.extend(int(x) for x in raw)
elif raw is not None:
ids.append(int(raw))
unk_id = getattr(tokenizer, "unk_token_id", None)
def _maybe_add_tid(tid: int) -> None:
if not isinstance(tid, int) or tid < 0:
return
if unk_id is not None and tid == unk_id:
return
if tid not in ids:
ids.append(tid)
model_type = getattr(hf_config, "model_type", None)
if model_type in ("qwen2", "qwen3", "qwen2_moe", "qwen3_moe"):
enc = getattr(tokenizer, "added_tokens_encoder", None)
if isinstance(enc, dict):
for key, tid in enc.items():
if isinstance(key, str) and "im_end" in key:
_maybe_add_tid(int(tid))
for extra in getattr(tokenizer, "additional_special_tokens", []) or []:
if not isinstance(extra, str) or "im_end" not in extra:
continue
try:
tid = tokenizer.convert_tokens_to_ids(extra)
except (TypeError, ValueError, KeyError):
continue
_maybe_add_tid(tid)
if not ids:
raise ValueError(
"Could not infer stop token ids from the tokenizer; set "
"LLMConfig(eos_token_ids=[...]) explicitly."
)
return ids
def _merge_apply_chat_template_kwargs(
tokenizer,
user_kwargs: Optional[dict[str, Any]],
) -> dict[str, Any]:
"""
Merge user kwargs with defaults for HF chat templates that support them.
Qwen3 (and similar) instruct models expect `add_generation_prompt=True` so
the first generated token continues the assistant turn; without it, output
can repeat punctuation / template fragments. `enable_thinking=False` avoids
the Qwen3 reasoning channel when the tokenizer supports it.
"""
out = dict(user_kwargs or {})
try:
sig = inspect.signature(tokenizer.apply_chat_template)
except (TypeError, ValueError):
return out
if "add_generation_prompt" in sig.parameters and "add_generation_prompt" not in out:
out["add_generation_prompt"] = True
if "enable_thinking" in sig.parameters and "enable_thinking" not in out:
out["enable_thinking"] = False
return out
def _runner_entry(config: LLMConfig, rank: int, evt):
runner = None
try:
runner = ModelRunner(config, rank, evt)
runner.loop()
except Exception as e:
logging.exception(f"Rank {rank}: {repr(e)}")
finally:
if runner is not None:
runner.exit()
class LLMEngine:
"""High-level engine coordinating model runners and scheduling"""
def __init__(self, config: LLMConfig, external_model: nn.Module | None = None):
self.config = config
if self.config.hf_config.model_type not in MODEL_REGISTRY:
raise ValueError(f"Unknown model {self.config.model}")
if config.path is None:
# Local directory: use it directly (no Hub round-trip).
try:
mp = Path(config.model)
if mp.is_dir() and (mp / "config.json").is_file():
self.config.path = str(mp.resolve())
logger.info("Using local model directory for tokenizer: %s", self.config.path)
except OSError:
pass
if config.path is None:
from huggingface_hub import snapshot_download
# Hub repo id: allow downloading missing shards/tokenizer files when cache
# is incomplete (local_files_only=False). Local dirs are handled above.
self.config.path = snapshot_download(
repo_id=config.model,
local_files_only=False,
)
logger.info(
"Resolved Hugging Face snapshot for %s @ %s",
self.config.model,
self.config.path,
)
assert self.config.path is not None
_trust = bool(getattr(self.config.hf_config, "trust_remote_code", False))
# Always load tokenizer from the resolved on-disk tree so we do not re-hit
# the Hub with the repo id (can re-download tokenizer / LFS shards).
self.tokenizer = AutoTokenizer.from_pretrained(
self.config.path,
use_fast=True,
trust_remote_code=_trust,
)
if self.config.eos_token_ids is None:
if self.config.eos != -1:
self.config.eos_token_ids = [int(self.config.eos)]
else:
self.config.eos_token_ids = _infer_stop_token_ids(
self.tokenizer, self.config.hf_config
)
else:
self.config.eos_token_ids = [int(x) for x in self.config.eos_token_ids]
self.config.eos_token_ids = sorted(set(self.config.eos_token_ids))
if self.config.eos == -1:
self.config.eos = int(self.config.eos_token_ids[0])
else:
self.config.eos = int(self.config.eos)
if self.config.eos not in self.config.eos_token_ids:
self.config.eos_token_ids = sorted(
self.config.eos_token_ids + [self.config.eos]
)
if external_model is not None and int(self.config.tensor_parallel_size) != 1:
raise ValueError(
"external_model (shared-weight compactor path) only supports "
"tensor_parallel_size=1"
)
self.ps = []
world_size = int(self.config.tensor_parallel_size)
self.events = []
if world_size > 1:
ctx = mp.get_context("spawn")
for r in range(1, world_size):
event = ctx.Event()
p = ctx.Process(
target=_runner_entry,
args=(self.config, r, event),
daemon=True,
)
p.start()
self.ps.append(p)
self.events.append(event)
self.master_model_runner = ModelRunner(
self.config,
rank=0,
peer_events=self.events,
external_model=external_model,
)
atexit.register(self.exit)
def exit(self):
if getattr(self, "_exited", False):
return
self._exited = True
runner = getattr(self, "master_model_runner", None)
if runner is not None:
try:
runner.exit()
except Exception:
logger.exception("Failed to exit master ModelRunner cleanly")
for p in self.ps:
if p.is_alive():
p.terminate()
p.join(timeout=1.0)
if hasattr(self, "events"):
self.events.clear()
def tokenize_prompt(self, prompt: PromptLike, **tokenizer_kwargs) -> List[int]:
"""
Turn a raw prompt into token IDs.
"""
if isinstance(prompt, str):
return self.tokenizer(prompt, **tokenizer_kwargs)["input_ids"]
else:
return list(prompt)
def detokenize_prompt(
self, sequences: List[Sequence], **detokenizer_kwargs
) -> List[str]:
"""
Turn completed Sequences into strings.
"""
defaults: dict[str, Any] = {"skip_special_tokens": True}
merged = {**defaults, **detokenizer_kwargs}
return self.tokenizer.batch_decode(
[s.completion_token_ids for s in sequences], **merged
)
def _build_sequences(
self,
prompts: List[PromptLike] | PromptLike,
sampling_params: SamplingParams | List[SamplingParams],
per_sequence_compression_params: Optional[
SequenceCompressionParams | List[SequenceCompressionParams]
] = None,
tokenizer_kwargs: Optional[dict[str, Any]] = None,
) -> List[Sequence]:
"""
Build Sequence objects from prompts, sampling params, and optional
per-sequence compression parameters.
"""
tokenizer_kwargs = {} if tokenizer_kwargs is None else tokenizer_kwargs
if not isinstance(prompts, list):
prompts = [prompts]
if isinstance(sampling_params, SamplingParams):
sampling_params_list: List[SamplingParams] = [sampling_params] * len(
prompts
)
else:
sampling_params_list = sampling_params
assert len(sampling_params_list) == len(prompts), (
"sampling_params list must match prompts length"
)
if per_sequence_compression_params is None:
compression_params_list: List[SequenceCompressionParams] = [
SequenceCompressionParams(1.0) for _ in prompts
]
elif isinstance(per_sequence_compression_params, SequenceCompressionParams):
compression_params_list = [per_sequence_compression_params] * len(prompts)
else:
# list-like
assert len(per_sequence_compression_params) == len(prompts), (
"per_sequence_compression_params list must match prompts length"
)
compression_params_list = list(per_sequence_compression_params)
seqs: List[Sequence] = []
for prompt, sparams, cparams in zip(
prompts, sampling_params_list, compression_params_list
):
token_ids = self.tokenize_prompt(prompt, **tokenizer_kwargs)
if cparams.protected_first_tokens + cparams.protected_last_tokens >= len(token_ids):
cparams.compression_ratio = 1.0
seqs.append(
Sequence(
prompt_token_ids=token_ids,
sampling_params=sparams,
compression_params=cparams,
)
)
return seqs
def generate(
self,
prompts: List[PromptLike] | PromptLike,
sampling_params: SamplingParams | List[SamplingParams],
batch_compression_params: BatchCompressionParams,
*,
per_sequence_compression_params: Union[
List[SequenceCompressionParams], SequenceCompressionParams
] = None,
tokenizer_kwargs: Optional[dict[str, Any]] = None,
detokenizer_kwargs: Optional[dict[str, Any]] = None,
return_sequences: bool = False,
) -> List[str] | tuple[List[str], List[Sequence]]:
"""
Accept prompts and return completed Sequences.
Args:
:param prompts:
Single prompt or list of prompts, each either a raw text prompt,
or pre-tokenized input IDs.
:param sampling_params:
A single SamplingParams for all prompts in this batch or a list of
SamplingParams with the same length as ``prompts``.
:param batch_compression_params:
Compression settings for this batch.
:param per_sequence_compression_params:
Per-sequence compression parameters, including the compression
ratio to be applied and the size of the protected regions of the
sequence (how many start tokens and end tokens to keep uncompressed).
If a SequenceCompressionParams instance, the same params will be
applied to all sequences in this batch; if a list is provided,
each SequenceCompressionParams will be attached to the corresponding
prompt in the batch.
:param tokenizer_kwargs:
Extra kwargs forwarded to ``tokenizer(...)`` when tokenizing
string prompts.
:param detokenizer_kwargs:
Passed through to `tokenizer.batch_decode`.
:param return_sequences:
Whether to return sequence objects or not
Returns:
:return List[Sequence]:
One Sequence per input prompt, with `completion_token_ids`
filled in after generation.
"""
tokenizer_kwargs = {} if tokenizer_kwargs is None else tokenizer_kwargs
detokenizer_kwargs = {} if detokenizer_kwargs is None else detokenizer_kwargs
seqs = self._build_sequences(
prompts,
sampling_params=sampling_params,
per_sequence_compression_params=per_sequence_compression_params,
tokenizer_kwargs=tokenizer_kwargs,
)
self.master_model_runner.generate(seqs, batch_compression_params)
output_strings = self.detokenize_prompt(seqs, **detokenizer_kwargs)
if return_sequences:
return output_strings, seqs
return output_strings
def generate_chat(
self,
messages_batch: List[List[dict]],
sampling_params: SamplingParams | List[SamplingParams],
batch_compression_params: BatchCompressionParams,
per_sequence_compression_params: Union[
SequenceCompressionParams, List[SequenceCompressionParams]
],
*,
tokenizer_kwargs: Optional[dict[str, Any]] = None,
detokenizer_kwargs: Optional[dict[str, Any]] = None,
return_sequences: bool = False,
) -> List[str] | tuple[List[str], List[Sequence]]:
"""
Convenience API for chat-style prompts using HF `apply_chat_template`.
Args:
:param messages_batch:
List of conversations, where each conversation is a list of
message dicts like:
{"role": "system" | "user" | "assistant", "content": str}
:param sampling_params:
A single SamplingParams for all prompts in this batch or a list of
SamplingParams with the same length as ``prompts``.
:param batch_compression_params:
Batch Level compression settings. Can set compression_method.
:param per_sequence_compression_params:
Per-sequence compression parameters, including the compression
ratio to be applied and the size of the protected regions of the
sequence (how many start tokens and end tokens to keep uncompressed).
If a SequenceCompressionParams instance, the same params will be
applied to all sequences in this batch; if a list is provided,
each SequenceCompressionParams will be attached to the corresponding
conversation in the batch.
:param tokenizer_kwargs:
Passed through to `tokenizer.apply_chat_template`.
:param detokenizer_kwargs:
Passed through to `tokenizer.batch_decode`.
:param return_sequences:
Whether to return sequence objects or not
Returns:
:return List[str] or tuple[List[str], List[Sequence]]:
One string per conversation.
"""
prompts_token_ids: List[List[int]] = []
tokenizer_kwargs = _merge_apply_chat_template_kwargs(
self.tokenizer, tokenizer_kwargs
)
detokenizer_kwargs = {} if detokenizer_kwargs is None else detokenizer_kwargs
for messages in messages_batch:
input_ids = self.tokenizer.apply_chat_template(
messages,
tokenize=True,
**tokenizer_kwargs,
)
if hasattr(input_ids, "tolist"):
input_ids = input_ids.tolist()
prompts_token_ids.append(input_ids)
return self.generate(
prompts_token_ids,
sampling_params=sampling_params,
batch_compression_params=batch_compression_params,
per_sequence_compression_params=per_sequence_compression_params,
tokenizer_kwargs=tokenizer_kwargs,
detokenizer_kwargs=detokenizer_kwargs,
return_sequences=return_sequences,
)
def generate_from_sequences(
self,
seqs: List[Sequence],
batch_compression_params: BatchCompressionParams,
) -> List[Sequence]:
"""
Args:
:param seqs:
List of Sequence instances
:param batch_compression_params:
Compression settings.
Returns:
:return List[Sequence]:
Same list, mutated in-place with completions.
"""
self.master_model_runner.generate(seqs, batch_compression_params)
return seqs
import logging
import os
from typing import Iterable, List, Optional
import torch
from vllm.kvprune.config.engine_config import LLMConfig
from vllm.kvprune.kv_cache.page_table import KVAllocationStatus, PagedKVCache
from vllm.kvprune.utils.tp_utils import kv_heads_shard_divisor
from torch import nn
logger = logging.getLogger(__name__)
class KVCacheManager:
def __init__(
self,
rank: int,
config: LLMConfig,
*,
device: str | None = None,
):
super().__init__()
hf_config = config.hf_config
self.rank = rank
self.gpu_frac = config.gpu_memory_utilization
self.page_size = config.kvcache_page_size
self.world_size = config.tensor_parallel_size
self.max_num_batches = config.max_num_seqs
self.max_model_len = config.max_model_len
self.num_layers = hf_config.num_hidden_layers
self.model_dtype = hf_config.torch_dtype
self.head_dim = getattr(hf_config, "head_dim", None)
self.max_pages_per_batch = (
self.max_model_len + self.page_size - 1
) // self.page_size
_ws = kv_heads_shard_divisor()
self.num_kv_heads = hf_config.num_key_value_heads // _ws
assert hf_config.num_key_value_heads % _ws == 0, (
"tensor-parallel world size needs to divide num_kv_heads"
)
self._cache_device = device if device is not None else f"cuda:{self.rank}"
self.num_pages = None
self.paged_cache: Optional[PagedKVCache] = None
self.max_batched_tokens = None
self.seq_id_to_batch = {}
def allocate_sequences(
self, seq_ids: List[int], max_positions: List[int]
) -> (bool, Optional[torch.Tensor]):
batch_mapping = []
for seq_id, len_to_alloc in zip(seq_ids, max_positions):
if seq_id not in self.seq_id_to_batch:
batch_id = self.paged_cache.new_batch()
if batch_id is None:
logger.warning("Failed to allocate batch!")
return False, None
self.seq_id_to_batch[seq_id] = int(batch_id)
batch_mapping.append(self.seq_id_to_batch[seq_id])
if (
alloc_status := self.paged_cache.reserve_tokens(
self.seq_id_to_batch[seq_id], len_to_alloc
)
) != KVAllocationStatus.SUCCESS:
logger.warning(f"Failed to allocate pages ({alloc_status})!")
return False, None
batch_mapping = torch.as_tensor(batch_mapping, dtype=torch.int32, device="cuda")
return True, batch_mapping
def free_sequences(self, seq_ids: Iterable[int]):
for seq_id in seq_ids:
global_batch_id = self.seq_id_to_batch.pop(seq_id, None)
self.paged_cache.free_batch(global_batch_id)
def init_cache(self, model: nn.Module):
self.num_pages = self.get_num_pages(self.gpu_frac, self.max_pages_per_batch)
self.paged_cache = PagedKVCache(
num_layers=self.num_layers,
H_kv=self.num_kv_heads,
head_dim=self.head_dim,
page_size=self.page_size,
num_pages=int(self.num_pages),
max_num_batches=self.max_num_batches,
device=self._cache_device,
dtype=self.model_dtype,
max_logical_pages_per_head=int(self.max_pages_per_batch),
)
self._assign_cache_to_layers(model)
def _assign_cache_to_layers(self, model) -> None:
for layer_index, layer in enumerate(model.model.layers):
attn = layer.self_attn.attn
k, v, pt, bh = self.paged_cache.layer_slices(layer_index)
attn.k_cache = k
attn.v_cache = v
attn.page_table = pt
attn.bh_seq_lens = bh
attn.page_size = self.page_size
def get_num_pages(self, frac: float, n_logical_pages_max: int):
free, total = torch.cuda.mem_get_info()
used = total - free
stats = torch.cuda.memory_stats()
peak = int(stats["allocated_bytes.all.peak"])
current = int(stats["allocated_bytes.all.current"])
bytes_for_kv_budget = int(total * frac * 0.9) - used - peak + current
if bytes_for_kv_budget <= 0:
# Standalone compactor: ``frac`` is a fraction of total VRAM. When a second
# engine shares the GPU with vLLM (shared weights), most VRAM is already
# committed; the formula above goes negative. Fall back to a slice of
# *currently free* memory for the compactor KV pool.
free_frac = float(
os.environ.get("VLLM_KVPRUNE_COMPACTOR_KV_FREE_FRAC", "0.55")
)
free_frac = max(0.05, min(free_frac, 0.95))
bytes_for_kv_budget = int(free * free_frac)
logger.warning(
"KV cache budget from gpu_memory_utilization (%.2f) is exhausted "
"(%.2f MiB free on device); using %.0f%% of free memory (~%.2f MiB) "
"for compactor KV (set VLLM_KVPRUNE_COMPACTOR_KV_FREE_FRAC to adjust).",
frac,
free / (1024**2),
free_frac * 100,
bytes_for_kv_budget / (1024**2),
)
if bytes_for_kv_budget <= 0:
raise RuntimeError(
"Insufficient memory for compactor KV cache: no free GPU memory left "
"after the primary vLLM engine. Lower vLLM gpu_memory_utilization or "
"max_model_len, shorten prompts, or run compactor-only / vLLM-only "
"sessions. Raising gpu_memory_utilization here does not help."
)
# page_table[L, B, H_kv, N_LOGICAL_PAGES_MAX] + bh_seq_lens[L, B, H_kv]
int32_sz = torch.empty((), dtype=torch.int32).element_size() # 4
page_table_bytes_per_layer = (
self.max_num_batches
* self.num_kv_heads
* n_logical_pages_max
* int32_sz # page_table
+ self.max_num_batches * self.num_kv_heads * int32_sz
)
total_page_table_bytes = self.num_layers * page_table_bytes_per_layer
kv_bytes_net = bytes_for_kv_budget - total_page_table_bytes
if kv_bytes_net <= 0:
# Tight VRAM: metadata alone can exceed the first budget; reserve page
# tables plus a slice of remaining free for KV tensors.
bytes_for_kv_budget = min(
int(free * 0.95),
total_page_table_bytes + max(int(free * 0.25), 8 * 1024 * 1024),
)
kv_bytes_net = bytes_for_kv_budget - total_page_table_bytes
if kv_bytes_net <= 0:
raise RuntimeError(
"page-table footprint exceeds available GPU memory for compactor KV. "
f"Reduce vLLM max_num_seqs (compactor uses {self.max_num_batches}) "
f"or max_model_len ({self.max_model_len}), or free GPU memory."
)
dtype_sz = torch.empty((), dtype=self.model_dtype).element_size()
bytes_per_page_across_layers = self.num_layers * (
2 * self.page_size * self.head_dim * dtype_sz
)
return max(1, kv_bytes_net // bytes_per_page_across_layers)
def estimate_max_batched_tokens(
self,
warmup_tokens: int,
bytes_used_before_warmup: int,
bytes_peak_after_warmup: int,
) -> int:
"""
Estimate the max total number of tokens that can be processed concurrently
without OOM.
"""
assert warmup_tokens > 0, "warmup_tokens must be > 0"
# activation bytes per token
warmup_delta = max(
0, int(bytes_peak_after_warmup) - int(bytes_used_before_warmup)
)
bytes_per_token = max(1, (warmup_delta + warmup_tokens - 1) // warmup_tokens)
free, total = torch.cuda.mem_get_info()
target = int(total * self.gpu_frac)
used_now = int(total - free)
# reserve headroom equal to the gap between peak and current allocations seen so far
stats = torch.cuda.memory_stats()
peak_cur = int(stats.get("allocated_bytes.all.peak", 0))
cur_now = int(stats.get("allocated_bytes.all.current", 0))
cushion = max(0, peak_cur - cur_now)
activation_budget = int(max(0, target - used_now - cushion) * 0.95)
max_tokens_per_batch = activation_budget // bytes_per_token
max_tokens_in_cache = (self.num_pages * self.page_size) // self.num_kv_heads
# round to lower multiple of page size
max_tokens_per_batch = (max_tokens_per_batch // self.page_size) * self.page_size
max_tokens_in_cache = (max_tokens_in_cache // self.page_size) * self.page_size
# When vLLM shares the same GPU, ``used_now`` often exceeds ``target`` (same
# situation as ``get_num_pages``), so activation_budget is ~0 and
# ``max_tokens_per_batch`` rounds to 0 or one page. The min(...) would then
# cap prefill at ~page_size tokens (e.g. 32) even though the compactor KV pool
# is large — no prompt longer than that can be scheduled. Prefer KV capacity
# (capped by max_model_len) whenever activation math yields only a token or two.
if (
max_tokens_in_cache > 0
and max_tokens_per_batch <= self.page_size
and max_tokens_in_cache > max_tokens_per_batch
):
max_tokens_per_batch = min(max_tokens_in_cache, self.max_model_len)
self.max_batched_tokens = min(max_tokens_in_cache, max_tokens_per_batch)
# Last resort: allow at least one page when KV exists but min(...) is still 0.
if self.max_batched_tokens == 0 and self.num_pages > 0 and max_tokens_in_cache > 0:
self.max_batched_tokens = min(max_tokens_in_cache, self.page_size)
return self.max_batched_tokens
@property
def num_free_batches(self) -> int:
return len(self.paged_cache.free_batches)
@property
def num_free_pages(self) -> int:
return min(len(fp) for fp in self.paged_cache.free_pages)
def reclaim_pages(
self,
seq_ids_to_reclaim: Iterable[int],
future_reserved_buffer: List[int] | torch.Tensor,
) -> int:
approximate_bytes_freed = 0
for i, seq_id in enumerate(seq_ids_to_reclaim):
batch_idx = self.seq_id_to_batch[seq_id]
approximate_bytes_freed += self.paged_cache.reclaim_pages(
batch_idx, future_reserved_buffer[i]
)
return approximate_bytes_freed
import atexit
import logging
import os
import inspect
from typing import Any, List, Optional
import torch
import torch.nn as nn
import torch.distributed as dist
from vllm.kvprune.attention.sparse_decode_kernel import num_splits_heuristic
from vllm.kvprune.compression.compression_config import BatchCompressionParams
from vllm.kvprune.config.constants import RESERVED_BATCH
from vllm.kvprune.config.engine_config import LLMConfig, KvpruneAttentionSchedule
from vllm.kvprune.core.memory_manager import KVCacheManager
from vllm.kvprune.core.scheduler import Scheduler
from vllm.kvprune.layers.sampler import Sampler
from vllm.kvprune.models import MODEL_REGISTRY
from vllm.kvprune.utils.arguments import (
DecodeBatchArguments,
DecodeBatchOutput,
PackedTensorArguments,
PrefillBatchArguments,
)
from vllm.kvprune.utils.context import CompressionContext, reset_context, set_context
from vllm.kvprune.utils.kv_dist import barrier_sync, broadcast_from_tp_rank0
from vllm.kvprune.utils.sequence import Sequence
from torch.multiprocessing import Event
from tqdm import tqdm
logger = logging.getLogger(__name__)
class ModelRunner:
"""Per-rank execution loop. Manages model, sampler, KV cache, and warmup"""
def __init__(
self,
config: LLMConfig,
rank: int,
batch_ready: Optional[Event] = None,
peer_events: List[Event] = None,
external_model: Optional[nn.Module] = None,
*,
embedded_in_vllm_worker: bool = False,
device: Optional[torch.device] = None,
):
self.config = config
self.embedded_in_vllm_worker = embedded_in_vllm_worker
if embedded_in_vllm_worker:
from vllm.distributed.parallel_state import (
get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size,
)
tp_ws = get_tensor_model_parallel_world_size()
tp_rank = get_tensor_model_parallel_rank()
if tp_ws != config.tensor_parallel_size:
raise RuntimeError(
f"tensor parallel world size {tp_ws} != "
f"LLMConfig.tensor_parallel_size {config.tensor_parallel_size}"
)
self.rank = tp_rank
_dev = device if device is not None else torch.device(
f"cuda:{torch.cuda.current_device()}"
)
if not dist.is_initialized():
raise RuntimeError(
"embedded_in_vllm_worker requires torch.distributed to be "
"initialized (vLLM worker)."
)
if dist.get_world_size() != tp_ws:
raise NotImplementedError(
"KV-prune compactor embedded in vLLM currently requires "
"dist.get_world_size() == tensor_parallel_size "
"(pipeline_parallel_size=1, data_parallel_size=1). "
f"Got dist.get_world_size()={dist.get_world_size()}, "
f"tp_ws={tp_ws}."
)
else:
self.rank = rank
_dev = device if device is not None else torch.device(f"cuda:{rank}")
self._device = _dev
assert config.eos_token_ids is not None and len(config.eos_token_ids) > 0, (
"LLMConfig.eos_token_ids must be set (filled in LLMEngine from tokenizer)."
)
self._stop_token_ids = torch.tensor(
config.eos_token_ids, dtype=torch.int64, device=_dev
)
hf_config = config.hf_config
self.enforce_eager = config.enforce_eager
if config.attention_schedule == KvpruneAttentionSchedule.PDFA:
if not self.enforce_eager and self.rank == 0:
logger.info(
"attention_schedule=PDFA: disabling compactor decode CUDA graphs "
"(FlashAttention decode path)."
)
self.enforce_eager = True
# Embedded in vLLM worker (TP>1): respect :attr:`LLMConfig.enforce_eager` from
# ``v1_tp_runner._apply_compactor_env_overrides``. Set
# ``VLLM_KVPRUNE_TP_EMBEDDED_GRAPH=0`` to force eager if graph replay is unstable
# with shared vLLM VRAM / streams / NCCL on your stack.
if embedded_in_vllm_worker:
_tp_graph = os.environ.get(
"VLLM_KVPRUNE_TP_EMBEDDED_GRAPH", "1"
).strip().lower()
if _tp_graph in ("0", "false", "no"):
if not self.enforce_eager:
logger.info(
"embedded_in_vllm_worker: VLLM_KVPRUNE_TP_EMBEDDED_GRAPH=0 → "
"forcing compactor enforce_eager=True (skip compactor CUDA graph "
"capture)."
)
self.enforce_eager = True
self.world_size = config.tensor_parallel_size
self.leverage_sketch_size = config.leverage_sketch_size
self.show_progress_bar = config.show_progress_bar
self.max_num_batches = config.max_num_seqs
self.max_model_len = config.max_model_len
self.num_layers = hf_config.num_hidden_layers
self.model_dtype = hf_config.torch_dtype
self.head_dim = getattr(hf_config, "head_dim", None)
init_kwargs = {}
if not embedded_in_vllm_worker:
if "device_id" in inspect.signature(dist.init_process_group).parameters:
init_kwargs["device_id"] = torch.device(f"cuda:{rank}")
if not dist.is_initialized():
dist.init_process_group(
"nccl",
f"tcp://localhost:{config.nccl_port}",
world_size=self.world_size,
rank=rank,
**init_kwargs,
)
else:
ws = dist.get_world_size()
if ws != self.world_size:
raise RuntimeError(
"torch.distributed is already initialized with "
f"world_size={ws}, but compactor ModelRunner expects "
f"tensor_parallel_size={self.world_size}. "
"Use tensor_parallel_size matching the active process group "
"(typically 1 when sharing weights with vLLM)."
)
torch.cuda.set_device(_dev)
default_dtype = torch.get_default_dtype()
torch.set_default_dtype(hf_config.torch_dtype)
torch.set_default_device("cuda")
model_type = hf_config.model_type
if external_model is not None:
self.model = external_model
else:
self.model = MODEL_REGISTRY[model_type](hf_config)
self.model.load_model(
config.path, use_tqdm=self.is_master and self.show_progress_bar
)
self.sampler = Sampler()
pre_warmup_mem = torch.cuda.memory_stats().get("allocated_bytes.all.current", 0)
# No paged KV yet: FA-only varlen path (see :meth:`warmup`).
self.warmup(num_warmup_tokens=self.max_model_len, with_kv=False)
post_warmup_peak = torch.cuda.memory_stats().get("allocated_bytes.all.peak", 0)
self.kv_manager = KVCacheManager(
self.rank, config, device=str(self._device)
)
self.kv_manager.init_cache(self.model)
self.store_stream: Optional[torch.cuda.Stream] = torch.cuda.Stream()
torch.set_default_device("cpu")
torch.set_default_dtype(default_dtype)
self.batch_ready = batch_ready
self.peer_events = peer_events if peer_events is not None else []
# Embedded TP peers: session end is signaled via TP-group broadcast in
# maybe_release_peers (no multiprocessing.Event — not pickleable over RPC).
self._embedded_peer_continue = True
self.captured_graphs = {}
self.min_captured_len = {}
self.max_batched_tokens = self.kv_manager.estimate_max_batched_tokens(
self.max_model_len, pre_warmup_mem, post_warmup_peak
)
if self.is_master:
logger.info(f"Estimated max batched tokens of {self.max_batched_tokens}")
self.warmup(num_warmup_tokens=self.max_model_len, with_kv=True)
if not self.enforce_eager:
bs = [1 << i for i in range(self.max_num_batches.bit_length())]
for bs in (
tqdm(bs, desc="Capturing CUDA Graphs")
if self.is_master and self.show_progress_bar
else bs
):
for seq_len in [1024, 4096, 8192, 16384]:
self.capture_cudagraph(bs, seq_len)
if not self.captured_graphs:
logger.warning(
"No compactor CUDA graphs were captured (KV budget tight or "
"allocate_sequences failed during capture). Using eager decode "
"for this session."
)
self.enforce_eager = True
self.packed_args = PackedTensorArguments(
rank=self.rank,
max_batched_tokens=self.max_batched_tokens,
config=self.config,
device=self._device,
use_tp_group_for_collectives=embedded_in_vllm_worker,
)
atexit.register(self.exit)
@torch.inference_mode()
def warmup(self, num_warmup_tokens: int, *, with_kv: bool):
sched = (
self.config.attention_schedule
if with_kv
else KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
)
if self.rank == 0:
logger.info(
"Warming up compactor attention (%s KV init): schedule=%s",
"after" if with_kv else "before",
sched.name,
)
device = self._device
input_ids = torch.tensor(
[self.config.eos] * num_warmup_tokens, device=device, dtype=torch.int64
)
positions = torch.arange(num_warmup_tokens, device=device, dtype=torch.int64)
cu_seqlens_q = torch.tensor(
[0, num_warmup_tokens], device=device, dtype=torch.int32
)
cu_seqlens_k = torch.tensor(
[0, num_warmup_tokens], device=device, dtype=torch.int32
)
if with_kv:
success, batch_mapping = self.kv_manager.allocate_sequences(
[-1], [num_warmup_tokens]
)
assert success
else:
batch_mapping = None
set_context(
is_prefill=True,
do_compression=False,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k=cu_seqlens_k,
cu_seqlens_q_host=(0, num_warmup_tokens),
cu_seqlens_k_host=(0, num_warmup_tokens),
max_seqlen_q=num_warmup_tokens,
max_seqlen_k=num_warmup_tokens,
batch_mapping=batch_mapping,
attention_schedule=sched,
)
for _ in range(2):
torch.cuda.reset_peak_memory_stats()
h = self.model(input_ids, positions)
self.model.compute_logits(h)
barrier_sync(use_tp_group=self.embedded_in_vllm_worker)
if with_kv:
self.kv_manager.paged_cache.bh_seq_lens.index_fill_(
1, batch_mapping.to(torch.long), 0
)
reset_context()
if with_kv:
self.kv_manager.free_sequences([-1])
def exit(self):
if getattr(self, "_exited", False):
return
self._exited = True
try:
if hasattr(self, "captured_graphs"):
self.captured_graphs.clear()
finally:
if getattr(self, "embedded_in_vllm_worker", False):
return
if dist.is_initialized():
dist.destroy_process_group()
def loop(self):
while True:
if self.batch_ready.wait(1.0):
self._process_batches_peer()
@torch.inference_mode()
def run_prefill(
self, prefill_args: PrefillBatchArguments, batch_mapping: torch.Tensor
):
assert prefill_args.B > 0 and prefill_args.N > 0
max_bh_len = (
self.kv_manager.paged_cache.bh_seq_lens.index_select(1, index=batch_mapping)
.max()
.item()
)
compression_context = CompressionContext(
compression_method=prefill_args.compression_method,
compression_chunk_size=prefill_args.compression_chunk_size,
batch_tokens_to_retain=prefill_args.batch_tokens_to_retain,
max_tokens_to_retain=prefill_args.max_tokens_to_retain,
context_lens=prefill_args.context_lens.tolist(),
PHI=prefill_args.PHI,
sketch_dimension=self.leverage_sketch_size,
protected_first_tokens=prefill_args.protected_first,
protected_last_tokens=prefill_args.protected_last,
compression_ratio=prefill_args.compression_ratio,
)
cu_q_host = tuple(
int(x) for x in prefill_args.cu_seqlens_q.detach().cpu().view(-1).tolist()
)
cu_k_host = tuple(
int(x) for x in prefill_args.cu_seqlens_k.detach().cpu().view(-1).tolist()
)
set_context(
is_prefill=True,
do_compression=prefill_args.do_compression,
cu_seqlens_q=prefill_args.cu_seqlens_q,
cu_seqlens_k=prefill_args.cu_seqlens_k,
cu_seqlens_q_host=cu_q_host,
cu_seqlens_k_host=cu_k_host,
max_seqlen_q=prefill_args.max_seqlen_q,
max_seqlen_k=prefill_args.max_seqlen_k,
batch_mapping=batch_mapping,
max_bh_len=max_bh_len,
compression_context=compression_context,
STORE_STREAM=self.store_stream,
attention_schedule=self.config.attention_schedule,
)
# int32 token ids break vLLM-delegated embedding (expects long indices) on some paths.
_iid = (
prefill_args.input_ids
if prefill_args.input_ids.dtype == torch.int64
else prefill_args.input_ids.long()
)
_pos = (
prefill_args.positions
if prefill_args.positions.dtype == torch.int64
else prefill_args.positions.long()
)
hidden = self.model(_iid, _pos)
logits = self.model.compute_logits(hidden)
reset_context()
return logits
def maybe_broadcast(self, tensor: torch.Tensor, *, label: str = "tensor") -> None:
if self.world_size > 1:
broadcast_from_tp_rank0(
tensor, use_tp_group=self.embedded_in_vllm_worker
)
return None
def maybe_release_peers(self, do_release=False):
if self.world_size <= 1:
return
if self.embedded_in_vllm_worker:
flag = torch.zeros(1, dtype=torch.int32, device=self._device)
if self.is_master:
flag[0] = 0 if do_release else 1
broadcast_from_tp_rank0(flag, use_tp_group=True)
if not self.is_master:
self._embedded_peer_continue = bool(flag[0].item())
barrier_sync(use_tp_group=True)
return
if self.is_master:
if do_release:
for event in self.peer_events:
event.clear()
barrier_sync(use_tp_group=False)
else:
barrier_sync(use_tp_group=False)
def _peer_outer_loop_active(self) -> bool:
if self.batch_ready is not None:
return self.batch_ready.is_set()
if self.embedded_in_vllm_worker:
return self._embedded_peer_continue
return False
@torch.inference_mode()
def generate(
self,
all_sequences: List[Sequence],
batch_compression_params: Optional[BatchCompressionParams] = None,
):
assert self.is_master, "generate can only be called on the master process"
if not self.embedded_in_vllm_worker:
for begin_execution_event in self.peer_events:
begin_execution_event.set()
if batch_compression_params is None:
batch_compression_params = BatchCompressionParams()
self._process_batches_master(all_sequences, batch_compression_params)
@property
def is_master(self):
return self.rank == 0
@torch.inference_mode()
def _process_batches_master(
self,
all_sequences: List[Sequence],
batch_compression_params: BatchCompressionParams,
):
assert self.is_master
compression_details = f"Applying Compression Method: {batch_compression_params.compression_method}"
if any(seq.compression_params.compression_ratio < 1.0 for seq in all_sequences):
logger.info(compression_details)
scheduler = Scheduler(
all_sequences=all_sequences,
kv_manager=self.kv_manager,
use_tqdm=self.show_progress_bar,
)
decode_batch = DecodeBatchArguments()
decode_flags = torch.empty(2, dtype=torch.int32, device=self._device)
while not scheduler.is_finished():
sequences = scheduler.get_prefill_batch()
if not sequences:
if scheduler.pending_sequence_ids:
raise RuntimeError(
"KV-prune compactor cannot schedule any prefill (KV/token budget). "
f"max_batched_tokens={self.kv_manager.max_batched_tokens}, "
f"pending_sequences={len(scheduler.pending_sequence_ids)}. "
"Lower v1 gpu_memory_utilization / max_model_len, set "
"VLLM_KVPRUNE_RELEASE_V1_KV=1 to discard v1 KV (sleep+wake), "
"or free GPU memory. Diagnostics: "
f"{scheduler.diagnose_prefill_failure()}"
)
# Pending is empty: either finished or decode-only continuation.
if decode_batch.token_ids is None:
break
run_decode = True
occupancy = -1
else:
seq_ids_cpu = [seq.seq_id for seq in sequences]
scheduler.add_running_sequence_ids(seq_ids_cpu, update_status=True)
temps = torch.tensor(
[s.sampling_params.temperature for s in sequences],
dtype=torch.float32,
pin_memory=True,
).to(device=self._device, non_blocking=True)
prefill_arguments = self.packed_args.build_prefill_args(
sequences, batch_compression_params=batch_compression_params
)
max_ctx_lens = (
prefill_arguments.max_new_tokens + prefill_arguments.context_lens
)
success, batch_mapping = self.kv_manager.allocate_sequences(
seq_ids_cpu, max_ctx_lens.tolist()
)
assert success, "failed to allocate pages for sequences"
logits = self.run_prefill(prefill_arguments, batch_mapping)
# Must match prefill `positions` dtype (int64). `context_lens` is int32
# from the packed buffer; using int32 here breaks RoPE indexing
# (`cos_sin_cache[positions]`) on CUDA for decode vs prefill.
positions = prefill_arguments.context_lens.to(dtype=torch.int64)
token_ids = self.sampler(logits, temps)
# Prefill KV writes + bh_seq_lens updates run on STORE_STREAM; reclaim
# reads bh_seq_lens on the default stream and must not race.
if self.store_stream is not None:
torch.cuda.default_stream().wait_stream(self.store_stream)
# TODO: synchronize page counts accross dist
if self.world_size == 1:
self.kv_manager.reclaim_pages(
seq_ids_cpu, prefill_arguments.max_new_tokens
)
# with logging_redirect_tqdm():
# logger.info(
# f"Reclaimed {reclaimed_bytes / 1e6:.2f} MB from the KV cache"
# )
if scheduler.any_pending_sequences():
num_pending_batches = (
0
if decode_batch.token_ids is None
else decode_batch.token_ids.shape[0]
)
occupancy = int((num_pending_batches + len(seq_ids_cpu)) * 0.66)
else:
occupancy = -1
run_decode = not scheduler.can_prefill_another_batch()
decode_batch = decode_batch.update(
batch_mapping,
token_ids,
positions,
max_ctx_lens,
prefill_arguments.seq_ids,
temps,
occupancy,
)
if self.world_size > 1:
decode_flags[0] = int(run_decode)
decode_flags[1] = occupancy
self.maybe_broadcast(decode_flags, label="decode_flags")
if not run_decode:
continue
if self.store_stream is not None:
torch.cuda.default_stream().wait_stream(self.store_stream)
decode_output, decode_batch = self.run_decode_loop(decode_batch)
finished_sequence_ids = scheduler.get_finished_sequence_ids_from_unfinished(
decode_batch.seq_ids.tolist()
)
scheduler.record_finished_sequence_ids(
finished_sequence_ids, update_status=True
)
self.kv_manager.free_sequences(finished_sequence_ids)
self.maybe_release_peers(scheduler.is_finished())
scheduler.update_sequences(
decode_output.output_tokens.tolist(),
decode_output.output_seq_ids.tolist(),
)
scheduler.close()
@torch.inference_mode()
def run_peer_session(self) -> None:
"""Non-master TP ranks: run one peer session (used when embedded in vLLM)."""
if self.embedded_in_vllm_worker:
self._embedded_peer_continue = True
self._process_batches_peer()
@torch.inference_mode()
def _process_batches_peer(self):
assert not self.is_master
scheduler = Scheduler([], kv_manager=self.kv_manager)
decode_batch = DecodeBatchArguments()
decode_flags = torch.empty(2, dtype=torch.int32, device=self._device)
while self._peer_outer_loop_active():
prefill_arguments = self.packed_args.build_prefill_args()
B = prefill_arguments.B
max_ctx_lens = (
prefill_arguments.max_new_tokens + prefill_arguments.context_lens
)
seq_ids_cpu = prefill_arguments.seq_ids.tolist()
scheduler.add_running_sequence_ids(seq_ids_cpu)
success, batch_mapping = self.kv_manager.allocate_sequences(
seq_ids_cpu, max_ctx_lens.tolist()
)
assert success, "failed to allocate pages for sequences"
self.run_prefill(prefill_arguments, batch_mapping)
positions = prefill_arguments.context_lens.to(dtype=torch.int64)
self.maybe_broadcast(decode_flags, label="decode_flags")
run_decode = bool(decode_flags[0].item())
occupancy = int(decode_flags[1].item())
token_ids = torch.empty(B, dtype=torch.int64, device=self._device)
decode_batch = decode_batch.update(
batch_mapping,
token_ids,
positions,
max_ctx_lens,
prefill_arguments.seq_ids,
None, # temps not used in peer process
occupancy,
)
if not run_decode:
continue
if self.store_stream is not None:
torch.cuda.default_stream().wait_stream(self.store_stream)
_, decode_batch = self.run_decode_loop(decode_batch)
finished_sequence_ids = scheduler.get_finished_sequence_ids_from_unfinished(
decode_batch.seq_ids.tolist()
)
scheduler.record_finished_sequence_ids(finished_sequence_ids)
self.kv_manager.free_sequences(finished_sequence_ids)
self.maybe_release_peers()
scheduler.close()
@torch.inference_mode()
def run_decode_loop(
self,
decode_batch: DecodeBatchArguments,
) -> tuple[DecodeBatchOutput, DecodeBatchArguments]:
if self.is_master:
num_stashed_batches = decode_batch.num_stashed_batches
tok_buffer = [
decode_batch.token_ids[num_stashed_batches:].to(
"cpu", non_blocking=True
)
]
seq_buffer = [
decode_batch.seq_ids[num_stashed_batches:].to("cpu", non_blocking=True)
]
while True:
self.maybe_broadcast(decode_batch.token_ids, label="decode_token_ids")
not_stopped = ~torch.isin(decode_batch.token_ids, self._stop_token_ids)
running_batches = (decode_batch.positions < decode_batch.max_ctx_lens) & (
not_stopped
)
decode_batch.token_ids = torch.masked_select(
decode_batch.token_ids, running_batches
)
decode_batch.positions = torch.masked_select(
decode_batch.positions, running_batches
)
decode_batch.batch_mapping = torch.masked_select(
decode_batch.batch_mapping, running_batches
)
decode_batch.max_ctx_lens = torch.masked_select(
decode_batch.max_ctx_lens, running_batches
)
decode_batch.seq_ids = torch.masked_select(
decode_batch.seq_ids, running_batches
)
if self.is_master:
decode_batch.temps = torch.masked_select(
decode_batch.temps, running_batches
)
num_remaining = decode_batch.token_ids.numel()
if (
num_remaining == 0
or num_remaining <= decode_batch.desired_batch_occupancy
):
decode_batch.num_stashed_batches = num_remaining
break
logits = self._decode_step_logits(decode_batch)
if self.is_master:
decode_batch.token_ids = self.sampler(logits, decode_batch.temps)
tok_buffer.append(decode_batch.token_ids.to("cpu", non_blocking=True))
seq_buffer.append(decode_batch.seq_ids.to("cpu", non_blocking=True))
decode_batch.positions += 1
if self.is_master:
# non_blocking D2H copies must finish before cat/tolist read CPU data.
torch.cuda.synchronize()
output = DecodeBatchOutput(
output_tokens=torch.cat(tok_buffer),
output_seq_ids=torch.cat(seq_buffer),
)
else:
output = DecodeBatchOutput(None, None)
return output, decode_batch
def _decode_logits_eager(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
batch_mapping: torch.Tensor,
):
set_context(
is_prefill=False,
do_compression=False,
batch_mapping=batch_mapping,
attention_schedule=self.config.attention_schedule,
)
_iid = input_ids if input_ids.dtype == torch.int64 else input_ids.long()
_pos = positions if positions.dtype == torch.int64 else positions.long()
hidden = self.model(_iid, _pos)
return self.model.compute_logits(hidden)
@torch.inference_mode()
def _decode_step_logits(self, decode_batch: DecodeBatchArguments):
"""Graph decode when possible; otherwise eager (never raises on missing graph)."""
if self.enforce_eager or not self.captured_graphs:
return self._decode_logits_eager(
decode_batch.token_ids,
decode_batch.positions,
decode_batch.batch_mapping,
)
try:
return self.run_graph_decode(
decode_batch.token_ids,
decode_batch.positions,
decode_batch.batch_mapping,
)
except Exception as e:
logger.warning(
"CUDA graph decode failed (%s); switching to eager decode for "
"remaining steps.",
e,
)
self.enforce_eager = True
return self._decode_logits_eager(
decode_batch.token_ids,
decode_batch.positions,
decode_batch.batch_mapping,
)
@torch.inference_mode()
def run_graph_decode(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
batch_mapping: torch.Tensor,
):
bs = input_ids.shape[0]
max_k = int(positions.max())
graph_dict = self.get_cuda_graph(bs, max_k)
if graph_dict is None:
return self._decode_logits_eager(input_ids, positions, batch_mapping)
set_context(
is_prefill=False,
do_compression=False,
batch_mapping=batch_mapping,
attention_schedule=self.config.attention_schedule,
)
graph_dict["input_ids"][:bs] = input_ids
graph_dict["positions"][:bs] = positions
graph_dict["batch_mapping"].fill_(RESERVED_BATCH)
graph_dict["batch_mapping"][:bs] = batch_mapping
graph_dict["graph"].replay()
logits_out = graph_dict["logits"]
return logits_out[:bs].contiguous()
@torch.inference_mode()
def capture_cudagraph(self, batch_size: int, max_seqlen_k: int):
barrier_sync(use_tp_group=self.embedded_in_vllm_worker)
device = torch.device("cuda")
logger.debug(
f"Capturing CUDA graph for batch size {batch_size} ({max_seqlen_k} tokens)"
)
_g_input_ids = torch.zeros(batch_size, dtype=torch.int32, device=device)
_g_positions = torch.zeros(batch_size, dtype=torch.int64, device=device)
_g_hidden = None
key_split = num_splits_heuristic(
batch_size * self.kv_manager.num_kv_heads,
max_seq_len=max_seqlen_k,
num_sms=torch.cuda.get_device_properties(device).multi_processor_count,
max_splits=12,
)
success, _g_batch_mapping = self.kv_manager.allocate_sequences(
list(range(batch_size)), [256] * batch_size
)
if not success:
# Shared GPU with vLLM: compactor KV pool is small; large batch capture
# often cannot reserve [256]*batch_size per sequence. Skip this graph.
logger.warning(
"Skipping CUDA graph capture for batch_size=%s max_seqlen_k=%s "
"(KV allocate_sequences failed; decode will use eager or other graphs).",
batch_size,
max_seqlen_k,
)
barrier_sync(use_tp_group=self.embedded_in_vllm_worker)
return
set_context(
is_prefill=False,
do_compression=False,
batch_mapping=_g_batch_mapping,
key_split=key_split,
attention_schedule=self.config.attention_schedule,
)
_gw = self.model(_g_input_ids, _g_positions)
self.model.compute_logits(_gw)
barrier_sync(use_tp_group=self.embedded_in_vllm_worker)
decode_graph = torch.cuda.CUDAGraph()
with torch.cuda.graph(decode_graph):
_g_hidden = self.model(_g_input_ids, _g_positions)
_g_logits = self.model.compute_logits(_g_hidden)
graph_vars = {
"graph": decode_graph,
"input_ids": _g_input_ids,
"positions": _g_positions,
"batch_mapping": _g_batch_mapping,
"hidden": _g_hidden,
"logits": _g_logits,
"key_split": key_split,
}
if batch_size not in self.captured_graphs:
self.captured_graphs[batch_size] = {}
self.min_captured_len[batch_size] = float("inf")
self.captured_graphs[batch_size][max_seqlen_k] = graph_vars
self.min_captured_len[batch_size] = min(
max_seqlen_k, self.min_captured_len[batch_size]
)
self.kv_manager.free_sequences(list(range(batch_size)))
def get_cuda_graph(
self, batch_size: int, max_seqlen_k: int
) -> Optional[dict[str, Any]]:
"""Return a captured graph dict, or None if no compatible capture exists."""
if not self.captured_graphs:
return None
eligible_bs = [x for x in self.captured_graphs.keys() if x >= batch_size]
if not eligible_bs:
return None
bs_key = min(eligible_bs)
batch_size_graphs = self.captured_graphs[bs_key]
candidates = [sl for sl in batch_size_graphs.keys() if sl <= max_seqlen_k]
if not candidates:
return None
best_sl = max(candidates)
return batch_size_graphs[best_sl]
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from __future__ import annotations
from dataclasses import dataclass
import torch
from vllm.forward_context import get_forward_context
from vllm.kvprune.core.compression_bridge import (
COMPRESSION_METHOD_ID_NONE,
compression_method_str_to_id,
)
@dataclass
class KVPruneForwardState:
"""Per-forward-pass state for KV pruning (per-layer logical lengths)."""
active: bool
compression_ratio_gpu: torch.Tensor
"""[num_reqs_padded] ratio in (0,1], 1.0 means no pruning for that row."""
compression_method_id_gpu: torch.Tensor
"""[num_reqs_padded] int32 — see ``compression_bridge`` ids (0=none)."""
query_start_loc: torch.Tensor
"""[num_reqs_padded + 1] int32 on device."""
num_reqs: int
num_reqs_padded: int
num_layers: int
logical_seq_lens_gpu: torch.Tensor
"""Logical KV length per layer (and optionally per KV head).
Shape ``[num_layers, num_reqs_padded]`` or, when ``num_kv_heads > 1``,
``[num_layers, num_reqs_padded, num_kv_heads]`` for per-head lengths.
"""
is_prefill: bool
device: torch.device
def logical_seq_lens_for_layer(self, layer_idx: int) -> torch.Tensor:
sl = self.logical_seq_lens_gpu[layer_idx]
if sl.dim() == 2:
return sl.max(dim=-1).values
return sl
def build_kv_prune_forward_state(
*,
req_ids: list[str],
requests: dict[str, object],
query_start_loc: torch.Tensor,
num_reqs: int,
num_reqs_padded: int,
num_layers: int,
max_num_scheduled_tokens: int,
device: torch.device,
logical_seq_lens_gpu: torch.Tensor,
) -> KVPruneForwardState | None:
"""Build pruning state when any request uses compression_ratio < 1.0."""
if num_reqs <= 0 or num_layers <= 0:
return None
ratios = []
method_ids: list[int] = []
active_req = False
for rid in req_ids[:num_reqs]:
req = requests.get(rid)
sp = getattr(req, "sampling_params", None) if req is not None else None
r = 1.0 if sp is None else float(getattr(sp, "compression_ratio", 1.0))
if r < 1.0 - 1e-6:
active_req = True
ratios.append(r)
if sp is None or r >= 1.0 - 1e-6:
mid = COMPRESSION_METHOD_ID_NONE
else:
cm = getattr(sp, "compression_method", "none") or "none"
mid = compression_method_str_to_id(str(cm))
method_ids.append(mid)
if not active_req:
return None
compression_ratio_gpu = torch.ones(
(num_reqs_padded,), dtype=torch.float32, device=device
)
compression_ratio_gpu[:num_reqs] = torch.tensor(
ratios, dtype=torch.float32, device=device
)
compression_method_id_gpu = torch.zeros(
(num_reqs_padded,), dtype=torch.int32, device=device
)
compression_method_id_gpu[:num_reqs] = torch.tensor(
method_ids, dtype=torch.int32, device=device
)
is_prefill = max_num_scheduled_tokens > 1
return KVPruneForwardState(
active=True,
compression_ratio_gpu=compression_ratio_gpu,
compression_method_id_gpu=compression_method_id_gpu,
query_start_loc=query_start_loc,
num_reqs=num_reqs,
num_reqs_padded=num_reqs_padded,
num_layers=num_layers,
logical_seq_lens_gpu=logical_seq_lens_gpu,
is_prefill=is_prefill,
device=device,
)
def layer_index_from_layer_name(layer_name: str) -> int:
from vllm.model_executor.models.utils import extract_layer_index
return extract_layer_index(layer_name)
def get_kv_prune_state() -> KVPruneForwardState | None:
try:
fc = get_forward_context()
except AssertionError:
return None
state = fc.additional_kwargs.get("kv_prune")
if state is None or not isinstance(state, KVPruneForwardState) or not state.active:
return None
return state
import time
from typing import Iterable, List
from vllm.kvprune.core.memory_manager import KVCacheManager
from vllm.kvprune.utils.sequence import Sequence, SequenceStatus
from tqdm import tqdm
def cdiv(a, b):
"""ceiling division"""
return (a + b - 1) // b
class Scheduler:
"""
Simple sequence scheduler for prefill + decode with a paged KV cache.
The scheduler tracks three disjoint sets of sequence IDs:
* ``pending_sequence_ids`` – sequences that have not yet been started.
* ``active_sequence_ids`` – sequences currently running.
* ``finished_sequence_ids`` – sequences that have generated all tokens.
At prefill time, :meth:`get_prefill_batch` selects a subset of pending
sequences that can fit into the available KV cache and per-step token
budget, given the constraints from the associated :class:`KVCacheManager`.
The class also handles basic bookkeeping of sequence statuses.
Args:
:param all_sequences:
Iterable of :class:`Sequence` objects to be scheduled. Each
sequence must have a unique ``seq_id``.
:param kv_manager:
A :class:`KVCacheManager` instance that this scheduler will use
to determine whether additional batches can be scheduled.
:param use_tqdm:
If True, two progress bars are created:
* "Started Batches" – increments when a sequence moves from
pending to running.
* "Finished Batches" – increments when a sequence finishes.
"""
def __init__(
self,
all_sequences: Iterable[Sequence],
kv_manager: KVCacheManager,
*,
use_tqdm=False,
):
self.allseq_mapping: dict[int, Sequence] = {s.seq_id: s for s in all_sequences}
self.pending_sequence_ids: set[int] = set([s.seq_id for s in all_sequences])
self.active_sequence_ids: set[int] = set()
self.finished_sequence_ids: set[int] = set()
self.manager = kv_manager
self.use_tqdm = use_tqdm
self.start_time = time.perf_counter()
self.total_tokens_generated = 0
self.total_tokens_input = 0
self.pbar = None
if use_tqdm:
self.pbar = tqdm(
total=len(self.pending_sequence_ids),
desc="Completed Batches",
)
def get_prefill_batch(self) -> List[Sequence]:
"""
Select a batch of pending sequences to prefill under KV/memory constraints.
The selection is greedy over ``pending_sequence_ids`` in iteration order.
A sequence is added to the batch if:
* The sum of its prompt length and the total prompt tokens selected so
far does not exceed ``manager.max_batched_tokens``, and
* There is at least one free KV "batch slot" left
(``manager.num_free_batches``), and
* The total number of KV pages required by the sequence's prompt +
max_new_tokens does not exceed the remaining free pages.
Returns:
:return List[Sequence]:
The list of :class:`Sequence` objects chosen for prefill in
this step. The caller is responsible for marking them as
active via :meth:`add_running_sequence_ids`.
"""
total_tok, sequences = 0, []
num_free_batches, num_free_pages = (
self.manager.num_free_batches,
self.manager.num_free_pages,
)
for seq_id in self.pending_sequence_ids:
seq = self.allseq_mapping[seq_id]
prompt_length = seq.prompt_len
pages_needed = (
cdiv(
prompt_length + seq.sampling_params.max_new_tokens,
self.manager.page_size,
)
* self.manager.num_kv_heads
)
if (
prompt_length + total_tok <= self.manager.max_batched_tokens
and num_free_batches > 0
and pages_needed <= num_free_pages
):
sequences.append(seq)
total_tok += prompt_length
num_free_pages -= pages_needed
num_free_batches -= 1
return sequences
def diagnose_prefill_failure(self) -> str:
"""Explain why :meth:`get_prefill_batch` may return empty (debugging)."""
num_free_batches = self.manager.num_free_batches
num_free_pages = self.manager.num_free_pages
parts = [
f"num_free_batches={num_free_batches}",
f"num_free_pages={num_free_pages}",
f"num_pages_per_layer={getattr(self.manager, 'num_pages', None)}",
]
seq_id = next(iter(self.pending_sequence_ids), None)
if seq_id is None:
return "; ".join(parts)
seq = self.allseq_mapping[seq_id]
pl = seq.prompt_len
mn = seq.sampling_params.max_new_tokens
pages_needed = (
cdiv(pl + mn, self.manager.page_size) * self.manager.num_kv_heads
)
parts.append(
f"first_pending seq_id={seq_id} prompt_len={pl} max_new_tokens={mn} "
f"pages_needed~={pages_needed}"
)
if num_free_batches == 0:
parts.append(
"likely_cause=no free batch slots (compactor max_num_seqs exhausted)"
)
elif pl > self.manager.max_batched_tokens:
parts.append(
f"likely_cause=prompt_len ({pl}) > max_batched_tokens "
f"({self.manager.max_batched_tokens})"
)
elif pages_needed > num_free_pages:
parts.append(
"likely_cause=KV pool too small: pages_needed exceeds num_free_pages "
"(raise VLLM_KVPRUNE_COMPACTOR_KV_FREE_FRAC / lower v1 memory, or cap "
"compactor max_num_seqs to shrink page-table overhead)"
)
else:
parts.append(
"likely_cause=batched token sum or greedy order (another sequence may "
"block first in set iteration)"
)
return "; ".join(parts)
def is_finished(self) -> bool:
"""
Check whether all sequences have completed.
"""
return (
len(self.pending_sequence_ids) == 0 and len(self.active_sequence_ids) == 0
)
def any_pending_sequences(self) -> bool:
"""
Check whether any sequences are still pending (not yet started).
"""
return len(self.pending_sequence_ids) != 0
def add_running_sequence_ids(
self, active_sequence_ids: Iterable[int], *, update_status: bool = False
):
"""
Mark a set of sequences as active / running. This moves sequence IDs
from ``pending_sequence_ids`` into ``active_sequence_ids``. Optionally,
it also updates the per-sequence status and progress bar.
Args:
:param active_sequence_ids:
Iterable of sequence IDs that have been scheduled for prefill
or decode and should now be considered running.
:param update_status:
If True, set each corresponding :class:`Sequence`'s
``status = SequenceStatus.RUNNING`` and increment the
"Started Batches" progress bar if ``use_tqdm`` is enabled.
"""
self.active_sequence_ids.update(active_sequence_ids)
self.pending_sequence_ids.difference_update(self.active_sequence_ids)
if update_status:
for seq_id in active_sequence_ids:
self.allseq_mapping[seq_id].status = SequenceStatus.RUNNING
self.total_tokens_input += self.allseq_mapping[seq_id].prompt_len
def get_finished_sequence_ids_from_unfinished(
self, unfinished_sequence_ids: Iterable[int]
) -> set[int]:
"""
Infer which active sequences have finished given the
unfinished set (for decode steps where the caller knows
which sequences are still generating but not necessarily
which have just completed).
Args:
:param unfinished_sequence_ids:
Iterable of sequence IDs that are still running
Returns:
:return set[int]:
The inferred set of sequence IDs that transitioned from active
to finished.
"""
return self.active_sequence_ids.difference(unfinished_sequence_ids)
def record_finished_sequence_ids(
self, finished_sequence_ids: Iterable[int], *, update_status: bool = False
):
"""
Record that a set of sequences has finished generation.
This moves IDs from ``active_sequence_ids`` into
``finished_sequence_ids``.
Args:
:param finished_sequence_ids:
Iterable of sequence IDs that have completed generation and
no longer require KV cache.
:param update_status:
If True, set each corresponding :class:`Sequence`'s
``status = SequenceStatus.FINISHED``
"""
self.active_sequence_ids.difference_update(finished_sequence_ids)
self.finished_sequence_ids.update(finished_sequence_ids)
if update_status:
for seq_id in finished_sequence_ids:
self.allseq_mapping[seq_id].status = SequenceStatus.FINISHED
if self.pbar is not None:
self.pbar.update(1)
def update_sequences(self, tokens: Iterable[int], seq_ids: Iterable[int]):
"""
Append newly generated tokens to their corresponding sequences.
Args:
:param tokens:
Iterable of generated token IDs, one per sequence.
:param seq_ids:
Iterable of sequence IDs aligned with ``tokens``.
"""
cur_time = time.perf_counter()
for tok, seq_id in zip(tokens, seq_ids):
self.allseq_mapping[seq_id].add_new_token(tok)
self.total_tokens_generated += 1
if self.pbar is not None:
self.pbar.set_description(
f"Throughput: {(self.total_tokens_generated + self.total_tokens_input) / (cur_time - self.start_time):.2f} tok/s"
)
def close(self):
if self.pbar is not None:
self.pbar.close()
def can_prefill_another_batch(self) -> bool:
return len(self.get_prefill_batch()) > 0
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""KV-pruning integration: compactor ``LLMEngine`` sharing weights with :class:`~vllm.LLM`."""
from vllm.kvprune.integration.compression_params import CompressionParams
__all__ = ["CompressionParams"]
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Construct compactor :class:`LLMEngine` sharing weight tensors with an in-process vLLM ``LLM``."""
from __future__ import annotations
import os
import torch.nn as nn
from vllm.config import VllmConfig
from vllm.kvprune.config.engine_config import LLMConfig
from vllm.kvprune.core.llm_engine import LLMEngine
from vllm.kvprune.integration.config_adapter import vllm_config_to_llm_config
from vllm.kvprune.integration.vllm_model_access import extract_vllm_causal_lm
from vllm.kvprune.integration.weight_tie import (
delegate_kvprune_compute_logits_to_vllm,
delegate_kvprune_embed_tokens_to_vllm,
tie_kvprune_rope_buffers_from_vllm,
tie_kvprune_weights_from_vllm,
)
from vllm.kvprune.models import MODEL_REGISTRY
from vllm.logger import init_logger
logger = init_logger(__name__)
def build_llm_config_for_compactor(vc: VllmConfig) -> LLMConfig:
"""Public helper: vLLM config → compactor :class:`LLMConfig`."""
return vllm_config_to_llm_config(vc)
def create_compactor_engine_with_shared_weights(llm: object) -> LLMEngine:
"""Single GPU, TP=1: compactor ``LLMEngine`` whose weights alias vLLM tensors.
Call after the vLLM ``LLM`` has loaded weights. Requires in-process executor
(``VLLM_ENABLE_V1_MULTIPROCESSING=0``).
"""
llm_engine = getattr(llm, "llm_engine", None)
if llm_engine is None:
raise RuntimeError("Expected ``llm.llm_engine``.")
vc: VllmConfig = llm_engine.vllm_config
if vc.parallel_config.tensor_parallel_size != 1:
raise ValueError(
"Shared-weight compactor backend requires tensor_parallel_size=1"
)
cfg = vllm_config_to_llm_config(vc)
# ``cfg.enforce_eager`` is for the compactor ``ModelRunner`` only (decode CUDA
# graphs), not v1. v1 graph capture is controlled solely by ``LLM(...,
# enforce_eager=...)`` / ``kvprune_compression=True`` on the entrypoint ``LLM``.
# Large vLLM max_num_seqs blows up compactor page-table GPU memory; sharing the GPU
# with v1 leaves little room for metadata + KV tensors. Default cap 32 so physical
# KV pages stay usable; set VLLM_KVPRUNE_COMPACTOR_MAX_NUM_SEQS=0 to disable cap,
# or raise (e.g. 128) if you have VRAM headroom.
_cap = os.environ.get("VLLM_KVPRUNE_COMPACTOR_MAX_NUM_SEQS", "32").strip()
if _cap:
lim = int(_cap)
if lim > 0:
cfg.max_num_seqs = min(cfg.max_num_seqs, lim)
# Compactor decode graphs (``enforce_eager=False``): honored for non-shared-weight
# engines. **Shared-weight** path (below) forces ``enforce_eager=True`` after
# delegating ``compute_logits`` to vLLM unless ``VLLM_KVPRUNE_SHARED_WEIGHT_GRAPH=1``.
# Opt out of graphs for non-shared runs: ``VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER=1`` or
# ``VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH=0``.
_ce = os.environ.get("VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER", "").strip().lower()
if _ce in ("1", "true", "yes"):
cfg.enforce_eager = True
logger.info(
"KV-prune compactor: VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER=1 → "
"enforce_eager=True (skip compactor decode CUDA graphs)."
)
elif _ce in ("0", "false", "no"):
cfg.enforce_eager = False
logger.info(
"KV-prune compactor: VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER=0 → "
"enforce_eager=False (try compactor CUDA graph capture)."
)
else:
_dg = os.environ.get(
"VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH", "1"
).strip().lower()
if _dg in ("0", "false", "no"):
cfg.enforce_eager = True
logger.info(
"KV-prune compactor: VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH=0 → "
"enforce_eager=True (skip compactor decode CUDA graphs)."
)
else:
cfg.enforce_eager = False
logger.info(
"KV-prune compactor: default try decode CUDA graphs; ModelRunner "
"falls back to eager if capture yields none. Set "
"VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER=1 or "
"VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH=0 to skip capture."
)
hf = cfg.hf_config
assert hf is not None
model_type = hf.model_type
if model_type not in MODEL_REGISTRY:
raise ValueError(
f"Compactor MODEL_REGISTRY has no entry for model_type={model_type!r}; "
f"supported: {sorted(MODEL_REGISTRY)}"
)
vllm_model = extract_vllm_causal_lm(llm)
device = next(vllm_model.parameters()).device
dtype = next(vllm_model.parameters()).dtype
# Build compactor shell on CPU first. **Do not** call ``.to(device)`` before tying:
# that allocates a full second copy of weights on GPU; tying then frees the
# duplicate but peak memory can OOM on large models. Tie first so parameters
# alias vLLM tensors directly (no extra weight VRAM).
kv_model: nn.Module = MODEL_REGISTRY[model_type](hf)
tie_kvprune_weights_from_vllm(vllm_model, kv_model)
# Buffers (e.g. RoPE tables) not in ``named_parameters`` may still be on CPU.
kv_model.to(device=device, dtype=dtype)
tie_kvprune_rope_buffers_from_vllm(vllm_model, kv_model)
delegate_kvprune_embed_tokens_to_vllm(vllm_model, kv_model)
delegate_kvprune_compute_logits_to_vllm(vllm_model, kv_model)
# Compactor decode CUDA graphs capture ``model.forward`` + ``compute_logits`` in one
# graph. Here ``compute_logits`` is delegated to vLLM's LM head / LogitsProcessor
# (cublas GEMM, padded vocab, etc.). Embedding that in a nested capture commonly
# fails with ``CUBLAS_STATUS_EXECUTION_FAILED`` and invalidates stream capture
# (``cudaErrorStreamCaptureInvalidated``). Default: skip graphs for this integration.
_sw_graph = os.environ.get(
"VLLM_KVPRUNE_SHARED_WEIGHT_GRAPH", "0"
).strip().lower() in ("1", "true", "yes")
if not _sw_graph:
cfg.enforce_eager = True
logger.info(
"KV-prune shared-weight compactor: enforce_eager=True (skip compactor "
"decode CUDA graphs; logits delegated to vLLM). Set "
"VLLM_KVPRUNE_SHARED_WEIGHT_GRAPH=1 only to attempt capture (often fails)."
)
return LLMEngine(cfg, external_model=kv_model)
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""KV-pruning (compactor) path invoked from :meth:`vllm.entrypoints.llm.LLM.generate`."""
from __future__ import annotations
import os
from collections.abc import Callable, Sequence
from pathlib import Path
from typing import Any
from tqdm.auto import tqdm
from transformers import AutoTokenizer
from vllm.kvprune.compression.compression_config import (
BatchCompressionParams,
SequenceCompressionParams,
)
from vllm.kvprune.config.sampling_params import SamplingParams as CompactorSamplingParams
from vllm.kvprune.core.compression_bridge import (
compression_method_id_to_enum,
compression_method_str_to_id,
)
from vllm.kvprune.core.llm_engine import LLMEngine, _infer_stop_token_ids
from vllm.kvprune.integration.compactor_shared import create_compactor_engine_with_shared_weights
from vllm.kvprune.integration.compression_params import CompressionParams
from vllm.logger import init_logger
from vllm.outputs import CompletionOutput, RequestOutput
from vllm.sampling_params import SamplingParams
logger = init_logger(__name__)
_MP_ENV = "VLLM_ENABLE_V1_MULTIPROCESSING"
_RELEASE_V1_KV_ENV = "VLLM_KVPRUNE_RELEASE_V1_KV"
def _maybe_release_v1_kv_for_compactor(llm: Any) -> None:
"""Optionally discard v1's KV cache so more GPU memory is free for compactor.
v1 reserves KV blocks at engine init; shared-weight compactor then competes for
the same VRAM. ``sleep(level=1)`` discards v1 KV and may offload tagged weights
per v1 sleep policy, then ``wake_up()`` reloads — compactor still ties the same
v1 tensors after.
**Default:** ``vllm.env_override`` sets ``VLLM_KVPRUNE_RELEASE_V1_KV=0`` (no
sleep/wake; v1 KV stays on GPU). Set ``=1`` if you need extra VRAM for compactor
before the first compressed step (then ``llm.sleep`` / ``CuMemAllocator`` /
``Sleep mode freed …`` logs are expected). This does **not** remove v1's KV
reservation at init; it only runs the optional sleep/wake cycle before compactor.
Tests keep ``VLLM_KVPRUNE_RELEASE_V1_KV=0`` in ``conftest``.
"""
if os.environ.get(_RELEASE_V1_KV_ENV, "0").strip().lower() not in (
"1",
"true",
"yes",
):
return
try:
logger.info(
"%s=1: discarding v1 KV via sleep(level=1) then wake_up() "
"(reloads model weights to GPU).",
_RELEASE_V1_KV_ENV,
)
llm.sleep(level=1, mode="abort")
llm.wake_up()
except Exception as e:
logger.warning("%s: sleep/wake failed: %s", _RELEASE_V1_KV_ENV, e)
def ensure_inprocess_engine_for_weight_sharing() -> None:
"""Compactor must see ``worker.get_model()`` in the same process as vLLM."""
if os.environ.get(_MP_ENV, "1") != "0":
os.environ[_MP_ENV] = "0"
logger.info(
"KV cache pruning: set %s=0 so the model stays in-process for "
"shared-weight compactor (no manual env needed).",
_MP_ENV,
)
def _normalize_prompt_list(prompts: Any) -> list[Any]:
if isinstance(prompts, str):
return [prompts]
if isinstance(prompts, dict):
return [prompts]
return list(prompts)
def _normalize_sampling_params(
sampling_params: SamplingParams | Sequence[SamplingParams] | None,
n: int,
) -> list[SamplingParams]:
if sampling_params is None:
return [SamplingParams() for _ in range(n)]
if isinstance(sampling_params, SamplingParams):
return [sampling_params] * n
sps = list(sampling_params)
if len(sps) != n:
raise ValueError(
f"sampling_params length {len(sps)} != prompts length {n}"
)
return sps
def _normalize_compression_params(
compression: CompressionParams | Sequence[CompressionParams] | None,
n: int,
) -> list[CompressionParams]:
if compression is None:
return [CompressionParams(compression_ratio=1.0) for _ in range(n)]
if isinstance(compression, CompressionParams):
return [compression] * n
comp = list(compression)
if len(comp) != n:
raise ValueError(f"compression length {len(comp)} != prompts length {n}")
return comp
def _any_compactor(comps: list[CompressionParams]) -> bool:
return any(c.compression_ratio < 1.0 for c in comps)
_FORCE_COMPACTOR_PATH_ENV = "VLLM_KVPRUNE_FORCE_COMPACTOR_PATH"
def _should_use_kvprune_compactor_path(comps: list[CompressionParams]) -> bool:
"""Use integrated compactor when any prompt requests compression, or when forced.
If all ``compression_ratio >= 1.0``, the default is to return ``None`` from
:func:`try_compressed_generate` and fall back to the standard v1 engine
(``Processed prompts`` loop). That hides TP/kvprune bugs behind a different
code path. Set ``VLLM_KVPRUNE_FORCE_COMPACTOR_PATH=1`` to run the same
compactor + collective RPC path as compression-on, with no KV pruning.
"""
if _any_compactor(comps):
return True
return os.environ.get(_FORCE_COMPACTOR_PATH_ENV, "").strip().lower() in (
"1",
"true",
"yes",
)
def _to_compactor_sampling(sp: SamplingParams) -> CompactorSamplingParams:
mt = sp.max_tokens
if mt is None:
mt = 16
return CompactorSamplingParams(
temperature=float(sp.temperature),
max_new_tokens=int(mt),
)
def _to_sequence_compression(cp: CompressionParams) -> SequenceCompressionParams:
return SequenceCompressionParams(
compression_ratio=float(cp.compression_ratio),
protected_first_tokens=int(cp.protected_first_tokens),
protected_last_tokens=int(cp.protected_last_tokens),
)
def _batch_compression_from_comps(comps: list[CompressionParams]) -> BatchCompressionParams:
for c in comps:
if c.compression_ratio < 1.0:
mid = compression_method_str_to_id(c.compression_method)
return BatchCompressionParams(
compression_method=compression_method_id_to_enum(mid)
)
return BatchCompressionParams()
def _kvprune_compactor_hf_tokenizer(llm: Any):
"""HF tokenizer matching :meth:`vllm.kvprune.core.llm_engine.LLMEngine.__init__`.
Loads from the **resolved on-disk** model tree (local dir or HF cache snapshot), not
the bare repo id, to avoid redundant Hub downloads.
"""
cached = getattr(llm, "_kvprune_compactor_hf_tokenizer", None)
if cached is not None:
return cached
mc = llm.llm_engine.vllm_config.model_config
model_s = str(mc.model)
src = model_s
try:
p = Path(model_s)
if p.is_dir() and (p / "config.json").is_file():
src = str(p.resolve())
else:
from huggingface_hub import snapshot_download
src = snapshot_download(repo_id=model_s, local_files_only=False)
except Exception:
src = model_s
hf_cfg = mc.hf_config
_trust = bool(getattr(hf_cfg, "trust_remote_code", False)) if hf_cfg is not None else False
tok = AutoTokenizer.from_pretrained(src, use_fast=True, trust_remote_code=_trust)
llm._kvprune_compactor_hf_tokenizer = tok
return tok
def _prompt_to_compactor_input(prompt: Any) -> str | list[int]:
if isinstance(prompt, str):
return prompt
# Decoder-only `list[int]` token ids (see `vllm.inputs.PromptType`).
if isinstance(prompt, list):
if not prompt:
raise TypeError("Empty token-id prompt is not supported for compactor path.")
if all(isinstance(t, int) for t in prompt):
return list(prompt)
if isinstance(prompt, dict):
if "prompt_token_ids" in prompt:
ids = prompt["prompt_token_ids"]
return list(ids) if not isinstance(ids, list) else ids
p = prompt.get("prompt")
if isinstance(p, str):
return p
raise TypeError(
f"Unsupported prompt type for compactor path: {type(prompt)}. "
"Use str, list[int] token ids, or dict with 'prompt_token_ids' or 'prompt'."
)
def _prompt_to_token_ids_for_tp(llm: Any, prompt: Any) -> list[int]:
"""Driver-side token ids for the TP collective path (same tokenizer as vLLM ``LLM``)."""
comp_in = _prompt_to_compactor_input(prompt)
if isinstance(comp_in, str):
return llm.get_tokenizer().encode(comp_in)
return list(comp_in)
def _compressed_generate_tp_collective(
llm: Any,
plist: list[Any],
sps: list[SamplingParams],
comps: list[CompressionParams],
) -> list[RequestOutput]:
"""TP>1: run compactor on each worker via ``collective_rpc`` (all ranks)."""
vc = llm.llm_engine.vllm_config
pc = vc.parallel_config
if pc.pipeline_parallel_size != 1 or pc.data_parallel_size != 1:
raise NotImplementedError(
"KV-prune TP compression requires pipeline_parallel_size=1 and "
f"data_parallel_size=1 (got PP={pc.pipeline_parallel_size}, "
f"DP={pc.data_parallel_size})."
)
hf = vc.model_config.hf_config
tok = llm.get_tokenizer()
eos_token_ids = _infer_stop_token_ids(tok, hf)
prompt_token_ids = [_prompt_to_token_ids_for_tp(llm, p) for p in plist]
max_len = int(vc.model_config.max_model_len)
for i, ids in enumerate(prompt_token_ids):
if len(ids) > max_len:
raise ValueError(
f"KV-prune TP compressed generate: prompt {i} length {len(ids)} "
f"exceeds max_model_len ({max_len}). Shorten the prompt or raise "
"max_model_len when constructing LLM()."
)
# Payload must be picklable for multiproc/Ray RPC: do not pass multiprocessing
# synchronization primitives (workers are separate processes).
payload: dict[str, Any] = {
"eos_token_ids": eos_token_ids,
"prompt_token_ids": prompt_token_ids,
"sampling_params": [
{
"temperature": float(sp.temperature),
"max_new_tokens": int(sp.max_tokens if sp.max_tokens is not None else 16),
}
for sp in sps
],
"compression_params": [
{
"compression_ratio": float(c.compression_ratio),
"compression_method": str(c.compression_method),
"protected_first_tokens": int(c.protected_first_tokens),
"protected_last_tokens": int(c.protected_last_tokens),
}
for c in comps
],
}
_maybe_release_v1_kv_for_compactor(llm)
try:
results = llm.llm_engine.collective_rpc(
"kvprune_v1_compressed_generate",
args=(payload,),
)
except RuntimeError as e:
if "cancelled" in str(e).lower():
raise RuntimeError(
"collective_rpc was cancelled (a GPU worker likely crashed). "
"Scroll up for the first worker traceback — often NCCL/CUDA before "
"TCPStore/Broken pipe on the driver."
) from e
raise
master: dict[str, Any] | None = None
for r in results:
if isinstance(r, dict) and r.get("tensor_parallel_rank") == 0:
master = r
break
if master is None:
raise RuntimeError(
"collective_rpc did not return a dict from tensor parallel rank 0."
)
return _tp_payload_to_request_outputs(llm, master)
def _tp_payload_to_request_outputs(llm: Any, master: dict[str, Any]) -> list[RequestOutput]:
tok = llm.get_tokenizer()
out: list[RequestOutput] = []
pids_list = master["prompt_token_ids"]
cids_list = master["completion_token_ids"]
for i, (pids, cids) in enumerate(zip(pids_list, cids_list)):
text = tok.decode(cids, skip_special_tokens=True)
co = CompletionOutput(
index=0,
text=text,
token_ids=list(cids),
cumulative_logprob=None,
logprobs=None,
finish_reason="stop",
)
ro = RequestOutput(
request_id=f"kvprune-tp-{i}",
prompt=None,
prompt_token_ids=list(pids),
prompt_logprobs=None,
outputs=[co],
finished=True,
)
out.append(ro)
return out
def _ensure_compactor_engine(llm: Any) -> LLMEngine:
if llm._kvprune_compactor_engine is None:
pc = llm.llm_engine.vllm_config.parallel_config
if pc.tensor_parallel_size != 1:
raise ValueError(
"KV-pruning compactor path requires tensor_parallel_size=1 "
"for shared weights."
)
llm._kvprune_compactor_engine = create_compactor_engine_with_shared_weights(llm)
logger.info("Initialized compactor LLMEngine with weights shared from vLLM.")
return llm._kvprune_compactor_engine
def try_compressed_generate(
llm: Any,
prompts: Any,
sampling_params: SamplingParams | Sequence[SamplingParams] | None,
*,
compression: CompressionParams | Sequence[CompressionParams] | None,
use_tqdm: bool | Callable[..., tqdm] = True,
lora_request: Any = None,
priority: list[int] | None = None,
tokenization_kwargs: dict[str, Any] | None = None,
) -> list[RequestOutput] | None:
"""Return completions on the compactor engine, or ``None`` to use normal v1.
``lora_request`` / ``priority`` / ``tokenization_kwargs`` are accepted for API
parity with :meth:`~vllm.entrypoints.llm.LLM.generate` but are not passed to the
compactor engine yet.
"""
del lora_request, priority, tokenization_kwargs, use_tqdm
plist = _normalize_prompt_list(prompts)
sps = _normalize_sampling_params(sampling_params, len(plist))
comps = _normalize_compression_params(compression, len(plist))
pc = llm.llm_engine.vllm_config.parallel_config
# TP>1: every worker must run the same collective_rpc session. If all
# compression_ratio >= 1, the old code returned None and only the driver ran
# v1 _run_engine — other ranks never joined a matching collective, which can
# deadlock NCCL / leave workers unsynchronized (hang at "Processed prompts:").
if pc.tensor_parallel_size > 1:
if not _should_use_kvprune_compactor_path(comps):
comps = [CompressionParams(compression_ratio=1.0) for _ in plist]
elif not _should_use_kvprune_compactor_path(comps):
return None
v1_eager = bool(
getattr(llm.llm_engine.vllm_config.model_config, "enforce_eager", False)
)
if not v1_eager:
logger.warning(
"KV-prune compression: v1 CUDA graphs are still enabled on this LLM. "
"The compactor does not reuse v1 graphs; capture wastes VRAM. "
"Set kvprune_compression=True, enforce_eager=True, or "
"VLLM_KVPRUNE_COMPRESSION_DEFAULT=1 before import vllm."
)
if pc.tensor_parallel_size > 1:
return _compressed_generate_tp_collective(llm, plist, sps, comps)
ensure_inprocess_engine_for_weight_sharing()
if llm._kvprune_compactor_engine is None:
_maybe_release_v1_kv_for_compactor(llm)
engine = _ensure_compactor_engine(llm)
comp_sp = [_to_compactor_sampling(sp) for sp in sps]
seq_c = [_to_sequence_compression(c) for c in comps]
batch_c = _batch_compression_from_comps(comps)
comp_in = [_prompt_to_compactor_input(p) for p in plist]
_, seqs = engine.generate(
comp_in,
sampling_params=comp_sp,
batch_compression_params=batch_c,
per_sequence_compression_params=seq_c,
return_sequences=True,
)
return _sequences_to_request_outputs(seqs, engine)
def _sequences_to_request_outputs(seqs: list[Any], engine: LLMEngine) -> list[RequestOutput]:
tok = engine.tokenizer
out: list[RequestOutput] = []
for i, seq in enumerate(seqs):
text = tok.decode(seq.completion_token_ids, skip_special_tokens=True)
# If every emitted id is “special” (e.g. EOS / chat boundary), the stripped
# string is empty while ``completion_token_ids`` is non-empty — avoid
# presenting a blank answer so users can see boundary tokens / debug.
if not text.strip() and seq.completion_token_ids:
text = tok.decode(seq.completion_token_ids, skip_special_tokens=False)
co = CompletionOutput(
index=0,
text=text,
token_ids=list(seq.completion_token_ids),
cumulative_logprob=None,
logprobs=None,
finish_reason="stop",
)
ro = RequestOutput(
request_id=f"kvprune-{i}",
prompt=None,
prompt_token_ids=list(seq.prompt_token_ids),
prompt_logprobs=None,
outputs=[co],
finished=True,
)
out.append(ro)
return out
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Per-request KV compression for :meth:`vllm.LLM.generate` (``compression=`` kwarg)."""
from __future__ import annotations
from dataclasses import dataclass
@dataclass
class CompressionParams:
"""Per-prompt compression intent for :meth:`vllm.LLM.generate`.
If **any** prompt in the batch has ``compression_ratio < 1.0``, the **whole** batch
is run on the compactor ``LLMEngine`` (same stack as standalone compactor-vllm:
``PagedKVCache`` + pruning kernels). If all prompts have ``compression_ratio >= 1.0``,
the batch stays on standard vLLM.
``compression_method`` follows :mod:`vllm.kvprune.core.compression_bridge` aliases:
``none``, ``criticaladakv``, ``compactor``, ``snapkv`` (ignored when
``compression_ratio`` is effectively 1).
``protected_*`` map to compactor :class:`~vllm.kvprune.compression.compression_config.SequenceCompressionParams`
(defaults match standalone compactor-vllm-style usage).
"""
compression_ratio: float = 1.0
compression_method: str = "compactor"
protected_first_tokens: int = 16
protected_last_tokens: int = 64
def __post_init__(self) -> None:
if not 0.0 < self.compression_ratio <= 1.0:
raise ValueError(
f"compression_ratio must be in (0, 1], got {self.compression_ratio}"
)
self.compression_method = (
self.compression_method or "compactor"
).strip().lower()
from vllm.kvprune.core.compression_bridge import VALID_ALIASES_FOR_SAMPLING
if self.compression_method not in VALID_ALIASES_FOR_SAMPLING:
raise ValueError(
f"compression_method must be one of {sorted(VALID_ALIASES_FOR_SAMPLING)}, "
f"got {self.compression_method!r}"
)
if self.compression_ratio >= 1.0 - 1e-9:
self.compression_method = "none"
elif self.compression_method == "none":
raise ValueError(
"When compression_ratio < 1.0, compression_method cannot be 'none'."
)
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Build :class:`vllm.kvprune.config.engine_config.LLMConfig` from :class:`VllmConfig`."""
from __future__ import annotations
import os
from pathlib import Path
from vllm.config import VllmConfig
from vllm.kvprune.config.engine_config import LLMConfig, KvpruneAttentionSchedule
from vllm.logger import init_logger
logger = init_logger(__name__)
def _attention_schedule_from_env() -> KvpruneAttentionSchedule:
"""Resolve :class:`KvpruneAttentionSchedule` from env.
Primary (``VLLM_KVPRUNE_ATTENTION_SCHEDULE``):
- ``fa_triton`` — FA prefill, Triton decode (default). Aliases: ``fa_prefill``,
``default``, empty.
- ``pdtriton`` — Triton prefill + Triton decode. Aliases: ``triton``,
``triton_prefill``, ``compactor_prefill``, ``pd_triton``.
- ``pdfa`` — FA prefill + FA decode (KV stores still Triton). Aliases:
``fa_full``, ``fa_both``.
Legacy: ``VLLM_KVPRUNE_ATTENTION_BACKEND`` maps ``flash``/``fa`` → ``fa_triton``,
``compactor``/``triton`` → ``pdtriton``.
"""
s = os.environ.get("VLLM_KVPRUNE_ATTENTION_SCHEDULE", "").strip().lower()
if s in ("fa_triton", "fa_prefill", "default", ""):
return KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
if s in ("pdtriton", "pd_triton", "triton", "triton_prefill", "compactor_prefill"):
return KvpruneAttentionSchedule.TRITON_PREFILL_TRITON_DECODE
if s in ("pdfa", "fa_full", "fa_both"):
return KvpruneAttentionSchedule.PDFA
if s:
logger.warning(
"Unknown VLLM_KVPRUNE_ATTENTION_SCHEDULE=%r; using FA_PREFILL_TRITON_DECODE",
s,
)
return KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
v = os.environ.get("VLLM_KVPRUNE_ATTENTION_BACKEND", "").strip().lower()
if v in ("flash", "fa", "flash_attention", "flashattention"):
return KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
if v in ("compactor", "triton", "compactor_triton", ""):
return KvpruneAttentionSchedule.TRITON_PREFILL_TRITON_DECODE
logger.warning(
"Unknown VLLM_KVPRUNE_ATTENTION_BACKEND=%r; using FA_PREFILL_TRITON_DECODE", v
)
return KvpruneAttentionSchedule.FA_PREFILL_TRITON_DECODE
def _compactor_kvcache_page_size(vllm_block_size: int | None) -> int:
"""Tokens per physical KV page for compactor :class:`LLMConfig`.
vLLM ``block_size`` is often 16; compactor ``head_sparse_decode_attention`` requires
``PAGE_SIZE % 32 == 0`` (see ``kvprune/attention/sparse_decode_kernel.py``). Standalone
compactor-vllm defaults to 128. Round up to the next multiple of 32 when needed.
"""
if vllm_block_size is None:
return 128
bs = int(vllm_block_size)
if bs <= 0:
return 128
if bs % 32 == 0:
return bs
return ((bs + 31) // 32) * 32
def vllm_config_to_llm_config(vc: VllmConfig) -> LLMConfig:
"""Map vLLM engine config to compactor :class:`LLMConfig`."""
mc = vc.model_config
cc = vc.cache_config
pc = vc.parallel_config
sc = vc.scheduler_config
block_size = cc.block_size
if block_size is None:
block_size = 16
max_num_seqs = getattr(sc, "max_num_seqs", 256)
# Do **not** forward ``model_config.enforce_eager`` (v1) into compactor
# :class:`LLMConfig`. They are independent flags: v1 uses it only to skip
# *v1* ``capture_model()``; kvprune :class:`~vllm.kvprune.core.model_runner.ModelRunner`
# uses :attr:`LLMConfig.enforce_eager` only for *compactor* decode CUDA graphs.
# Shared-weight setup in ``compactor_shared`` defaults compactor to eager decode;
# see ``VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH`` (default try graphs) /
# ``VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER``.
# Local checkpoint directory: forward so compactor skips redundant Hub fetches.
_model_s = str(mc.model)
_path: str | None = None
try:
if _model_s and Path(_model_s).is_dir() and (Path(_model_s) / "config.json").is_file():
_path = str(Path(_model_s).resolve())
except OSError:
pass
return LLMConfig(
model=_model_s,
path=_path,
nccl_port=1218,
max_num_seqs=max_num_seqs,
max_model_len=mc.max_model_len,
gpu_memory_utilization=cc.gpu_memory_utilization,
tensor_parallel_size=pc.tensor_parallel_size,
enforce_eager=False,
hf_config=mc.hf_config,
eos=-1,
eos_token_ids=None,
kvcache_page_size=_compactor_kvcache_page_size(block_size),
leverage_sketch_size=48,
attention_schedule=_attention_schedule_from_env(),
attention_backend=None,
)
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""TP>1: one kvprune :class:`~vllm.kvprune.core.model_runner.ModelRunner` per vLLM worker.
Invoked via v1 ``collective_rpc("kvprune_v1_compressed_generate", ...)`` so every tensor-
parallel rank participates in the same compactor forward/broadcast sequence as the
standalone multi-process compactor.
Compactor decode CUDA graphs (when not ``enforce_eager``) capture the full decode step
including ``compute_logits``. To force eager on embedded TP workers, set
``VLLM_KVPRUNE_TP_EMBEDDED_GRAPH=0`` or ``VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER=1``.
Peer/master session boundaries use TP-group ``broadcast``/``barrier`` (see
``ModelRunner.maybe_release_peers``), not ``multiprocessing.Event`` — RPC payloads must
be picklable across worker processes.
"""
from __future__ import annotations
import os
from typing import Any
import torch
import torch.nn as nn
from vllm.kvprune.compression.compression_config import (
BatchCompressionParams,
SequenceCompressionParams,
)
from vllm.kvprune.config.sampling_params import SamplingParams as CompactorSamplingParams
from vllm.kvprune.core.compression_bridge import (
compression_method_id_to_enum,
compression_method_str_to_id,
)
from vllm.kvprune.core.model_runner import ModelRunner
from vllm.kvprune.integration.config_adapter import vllm_config_to_llm_config
from vllm.kvprune.utils.kv_dist import barrier_sync
from vllm.kvprune.integration.weight_tie import (
delegate_kvprune_compute_logits_to_vllm,
delegate_kvprune_embed_tokens_to_vllm,
tie_kvprune_rope_buffers_from_vllm,
tie_kvprune_weights_from_vllm,
)
from vllm.kvprune.models import MODEL_REGISTRY
from vllm.kvprune.utils.sequence import Sequence
_ATTR = "_kvprune_tp_embedded_runner"
def _apply_compactor_env_overrides(cfg: Any) -> None:
"""Match :func:`~vllm.kvprune.integration.compactor_shared.create_compactor_engine_with_shared_weights` caps."""
_cap = os.environ.get("VLLM_KVPRUNE_COMPACTOR_MAX_NUM_SEQS", "32").strip()
if _cap:
lim = int(_cap)
if lim > 0:
cfg.max_num_seqs = min(cfg.max_num_seqs, lim)
_ce = os.environ.get("VLLM_KVPRUNE_COMPACTOR_ENFORCE_EAGER", "").strip().lower()
if _ce in ("1", "true", "yes"):
cfg.enforce_eager = True
elif _ce in ("0", "false", "no"):
cfg.enforce_eager = False
else:
_dg = os.environ.get("VLLM_KVPRUNE_COMPACTOR_CUDA_GRAPH", "1").strip().lower()
cfg.enforce_eager = _dg in ("0", "false", "no")
def _build_sequences(payload: dict[str, Any]) -> list[Sequence]:
prompt_ids: list[list[int]] = payload["prompt_token_ids"]
sps: list[dict[str, Any]] = payload["sampling_params"]
cps: list[dict[str, Any]] = payload["compression_params"]
seqs: list[Sequence] = []
for i, ids in enumerate(prompt_ids):
sp = CompactorSamplingParams(
temperature=float(sps[i]["temperature"]),
max_new_tokens=int(sps[i]["max_new_tokens"]),
)
cp = SequenceCompressionParams(
compression_ratio=float(cps[i]["compression_ratio"]),
protected_first_tokens=int(cps[i].get("protected_first_tokens", 16)),
protected_last_tokens=int(cps[i].get("protected_last_tokens", 64)),
)
if cp.protected_first_tokens + cp.protected_last_tokens >= len(ids):
cp.compression_ratio = 1.0
seqs.append(
Sequence(
prompt_token_ids=list(ids),
sampling_params=sp,
compression_params=cp,
)
)
return seqs
def _batch_compression_from_payload(payload: dict[str, Any]) -> BatchCompressionParams:
cps = payload["compression_params"]
for c in cps:
if float(c["compression_ratio"]) < 1.0:
mid = compression_method_str_to_id(str(c.get("compression_method", "none")))
return BatchCompressionParams(
compression_method=compression_method_id_to_enum(mid)
)
return BatchCompressionParams()
def _get_or_create_runner(worker: Any, payload: dict[str, Any]) -> ModelRunner:
existing = getattr(worker, _ATTR, None)
if existing is not None:
return existing
from vllm.distributed.parallel_state import (
get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size,
)
vc = worker.vllm_config
pc = vc.parallel_config
if pc.pipeline_parallel_size != 1 or pc.data_parallel_size != 1:
raise NotImplementedError(
"KV-prune TP compressed generate requires pipeline_parallel_size=1 and "
f"data_parallel_size=1; got PP={pc.pipeline_parallel_size}, "
f"DP={pc.data_parallel_size}."
)
tp_ws = get_tensor_model_parallel_world_size()
if tp_ws != pc.tensor_parallel_size:
raise RuntimeError(
f"parallel_state TP world size {tp_ws} != config.tensor_parallel_size "
f"{pc.tensor_parallel_size}"
)
hf = vc.model_config.hf_config
model_type = getattr(hf, "model_type", None)
if model_type not in MODEL_REGISTRY:
raise ValueError(
f"KV-prune TP path: unsupported model_type={model_type!r}; "
f"registry has {sorted(MODEL_REGISTRY)}"
)
cfg = vllm_config_to_llm_config(vc)
eos_ids = payload["eos_token_ids"]
cfg.eos_token_ids = sorted({int(x) for x in eos_ids})
cfg.eos = int(cfg.eos_token_ids[0])
_apply_compactor_env_overrides(cfg)
vllm_model = worker.get_model()
kv_model: nn.Module = MODEL_REGISTRY[model_type](hf)
tie_kvprune_weights_from_vllm(vllm_model, kv_model)
dev = next(vllm_model.parameters()).device
dtype = next(vllm_model.parameters()).dtype
kv_model.to(device=dev, dtype=dtype)
tie_kvprune_rope_buffers_from_vllm(vllm_model, kv_model)
delegate_kvprune_embed_tokens_to_vllm(vllm_model, kv_model)
delegate_kvprune_compute_logits_to_vllm(vllm_model, kv_model)
tp_rank = get_tensor_model_parallel_rank()
device = torch.device(f"cuda:{torch.cuda.current_device()}")
if tp_rank == 0:
runner = ModelRunner(
cfg,
rank=0,
peer_events=[],
external_model=kv_model,
embedded_in_vllm_worker=True,
device=device,
)
else:
runner = ModelRunner(
cfg,
rank=tp_rank,
batch_ready=None,
external_model=kv_model,
embedded_in_vllm_worker=True,
device=device,
)
setattr(worker, _ATTR, runner)
return runner
def run_kvprune_tp_compressed_generate(worker: Any, payload: dict[str, Any]) -> dict[str, Any]:
"""Execute one compressed generation session on this worker (all TP ranks)."""
from vllm.distributed.parallel_state import get_tensor_model_parallel_rank
tp_rank = get_tensor_model_parallel_rank()
runner = _get_or_create_runner(worker, payload)
sequences = _build_sequences(payload)
batch_c = _batch_compression_from_payload(payload)
barrier_sync(use_tp_group=True)
if tp_rank == 0:
runner.generate(sequences, batch_c)
return {
"tensor_parallel_rank": 0,
"prompt_token_ids": [list(s.prompt_token_ids) for s in sequences],
"completion_token_ids": [list(s.completion_token_ids) for s in sequences],
}
runner.run_peer_session()
return {"tensor_parallel_rank": int(tp_rank), "ok": True}
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Access the in-process vLLM model weights for compactor weight sharing."""
from __future__ import annotations
import torch.nn as nn
from vllm.logger import init_logger
logger = init_logger(__name__)
def extract_vllm_causal_lm(llm: object) -> nn.Module:
"""Return the root ``nn.Module`` holding transformer + lm_head from a v1 ``LLM``.
Requires ``LLMEngine`` to have been constructed with ``multiprocess_mode=False``
so ``model_executor`` lives in-process (set ``VLLM_ENABLE_V1_MULTIPROCESSING=0``).
"""
llm_engine = getattr(llm, "llm_engine", None)
if llm_engine is None:
raise RuntimeError("Expected an object with a ``llm_engine`` attribute (e.g. ``vllm.LLM``).")
ex = getattr(llm_engine, "model_executor", None)
if ex is None:
raise RuntimeError(
"model_executor is unavailable (multiprocess engine mode). "
"Set environment variable VLLM_ENABLE_V1_MULTIPROCESSING=0 for "
"in-process weight sharing."
)
driver = getattr(ex, "driver_worker", None)
if driver is None:
raise RuntimeError(
"Executor has no driver_worker (unexpected executor type for weight sharing)."
)
worker = getattr(driver, "worker", None)
if worker is None:
raise RuntimeError("Worker wrapper has no worker loaded.")
get_model = getattr(worker, "get_model", None)
if not callable(get_model):
raise RuntimeError("Worker does not expose get_model().")
return get_model()
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Share vLLM parameter storage with compactor ``MODEL_REGISTRY`` models (TP=1)."""
from __future__ import annotations
import types
import torch
import torch.nn as nn
from vllm.kvprune.utils.context import get_context
from vllm.logger import init_logger
logger = init_logger(__name__)
def tie_kvprune_weights_from_vllm(
vllm_model: nn.Module,
kvprune_model: nn.Module,
*,
strict: bool = True,
) -> int:
"""Point compactor parameters to the same tensors as vLLM where names match.
Returns the number of parameters tied. Requires identical parameter names
and shapes for overlapping weights (typical when both stacks mirror HF
naming for the same architecture).
Args:
vllm_model: Model returned by ``worker.get_model()`` (e.g. ``Qwen3ForCausalLM``).
kvprune_model: Instance from ``vllm.kvprune.models.MODEL_REGISTRY``.
strict: If True, raise when any ``kvprune`` parameter name is missing from
``vllm_model`` or shapes differ.
"""
vd = dict(vllm_model.named_parameters())
kd = dict(kvprune_model.named_parameters())
tied = 0
for name, kp in kd.items():
if name not in vd:
if strict:
raise ValueError(
f"kvprune parameter {name!r} not found in vLLM model; "
"architecture/layout may differ (disable strict tying only "
"for expert debugging)."
)
continue
vp = vd[name]
if vp.shape != kp.shape:
raise ValueError(
f"Shape mismatch for {name}: vllm {vp.shape} vs kvprune {kp.shape}"
)
kp.data = vp.data
tied += 1
if tied == 0:
raise ValueError(
"No parameters were tied — check that vLLM and kvprune model types match "
"and use the same state_dict names."
)
logger.info("Tied %d parameters from vLLM into compactor model (shared storage).", tied)
return tied
def tie_kvprune_rope_buffers_from_vllm(
vllm_model: nn.Module,
kvprune_model: nn.Module,
) -> int:
"""Copy RoPE ``cos_sin_cache`` buffers from vLLM into kvprune.
:func:`tie_kvprune_weights_from_vllm` only aliases :class:`~torch.nn.Parameter`
tensors. RoPE tables live in buffers; kvprune's simplified ``RotaryEmbedding``
can disagree with vLLM's ``rope_parameters`` (YaRN, etc.). Copying
``cos_sin_cache`` after ``.to(device, dtype)`` keeps Q/K rotation aligned with
the main model.
kvprune uses layout ``[max_len, 1, rotary_dim]``; vLLM uses ``[max_len,
rotary_dim]``. The singleton dim is filled via ``unsqueeze(1)`` on the vLLM
tensor when copying.
"""
vd = dict(vllm_model.named_buffers())
copied = 0
for name, kb in kvprune_model.named_buffers():
if "cos_sin_cache" not in name:
continue
if name not in vd:
logger.warning(
"kvprune RoPE buffer %r not found in vLLM; leaving kvprune cache",
name,
)
continue
vb = vd[name]
if vb.shape == kb.shape:
kb.copy_(vb)
copied += 1
elif kb.dim() == 3 and vb.dim() == 2:
if (
kb.shape[0] != vb.shape[0]
or kb.shape[2] != vb.shape[1]
or kb.shape[1] != 1
):
raise ValueError(
f"cos_sin_cache shape mismatch for {name!r}: "
f"vLLM {tuple(vb.shape)} vs kvprune {tuple(kb.shape)}"
)
kb.copy_(vb.unsqueeze(1))
copied += 1
else:
raise ValueError(
f"Unsupported cos_sin_cache layout for {name!r}: "
f"vLLM {tuple(vb.shape)} vs kvprune {tuple(kb.shape)}"
)
if copied:
logger.info(
"Copied %d RoPE cos_sin_cache buffer(s) from vLLM into kvprune model.",
copied,
)
return copied
def delegate_kvprune_embed_tokens_to_vllm(
vllm_model: nn.Module,
kvprune_model: nn.Module,
) -> bool:
"""Use vLLM's ``model.embed_tokens`` forward for kvprune (TP-safe token→shard mapping).
Even with tied weights, kvprune's simplified contiguous
``VocabParallelEmbedding`` (``vocab_start = rank * partition``) can disagree with
vLLM's padded vocabulary and org/added shard ranges, producing invalid indices for
``F.embedding`` on non-zero TP ranks (``index_copy_`` / device-side assert).
Delegating the forward to vLLM's embedding module keeps masks and indices aligned
with the main model while parameters remain shared storage.
"""
if not hasattr(vllm_model, "model") or not hasattr(kvprune_model, "model"):
return False
vm = getattr(vllm_model.model, "embed_tokens", None)
km = getattr(kvprune_model.model, "embed_tokens", None)
if vm is None or km is None:
logger.warning(
"delegate_kvprune_embed_tokens_to_vllm: embed_tokens missing; skipped"
)
return False
def _forward(_self_unused: nn.Module, x):
return vm(x)
km.forward = types.MethodType(_forward, km)
logger.info(
"kvprune model.embed_tokens forward delegated to vLLM (correct vocab-parallel masks)."
)
return True
def delegate_kvprune_compute_logits_to_vllm(
vllm_model: nn.Module,
kvprune_model: nn.Module,
) -> bool:
"""Route ``kvprune_model.compute_logits`` through vLLM's ``compute_logits``.
Standalone compactor used :class:`~vllm.kvprune.layers.embed_head.ParallelLMHead`
with ``F.linear`` + TP gather. vLLM applies :class:`~vllm.model_executor.layers.logits_processor.LogitsProcessor`
(gather/all-gather, padded-vocab trim, quant hooks). Mismatch here commonly
produces garbage token distributions while the rest of the stack looks fine.
After weight tying, ``vllm_model.compute_logits(hidden)`` uses the same lm_head
storage as kvprune; only the *application* path matches production vLLM.
"""
if not callable(getattr(vllm_model, "compute_logits", None)):
logger.warning(
"delegate_kvprune_compute_logits_to_vllm: vLLM model has no compute_logits; skipped"
)
return False
def _compute_logits(_self: nn.Module, hidden_states):
# Match kvprune :class:`~vllm.kvprune.layers.embed_head.ParallelLMHead`:
# prefill logits are for the **last** token of each packed sequence only.
context = get_context()
if context.is_prefill and context.cu_seqlens_q is not None:
cuq = context.cu_seqlens_q
last_indices = (cuq[1:] - 1).to(torch.long)
n_tok = hidden_states.shape[0]
if n_tok > 0:
last_indices = last_indices.clamp(min=0, max=n_tok - 1)
hidden_states = hidden_states[last_indices].contiguous()
# vLLM lm_head + gather expect contiguous activations; non-contiguous views have
# caused garbage logits under TP in edge cases.
hidden_states = hidden_states.contiguous()
logits = vllm_model.compute_logits(hidden_states)
return logits
kvprune_model.compute_logits = types.MethodType(_compute_logits, kvprune_model)
return True
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Paged KV cache helpers and Triton KV store."""
from vllm.kvprune.kv_cache.store_kv_cache import (
decode_store_kv,
prefill_store_all_kv,
prefill_store_topk_kv,
)
__all__ = [
"decode_store_kv",
"prefill_store_all_kv",
"prefill_store_topk_kv",
]
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment